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18685020020 = 2251618957709
BaseRepresentation
bin10001011001101101…
…101100011101110100
31210020012011100211112
4101121231230131310
5301231331120040
612330032454152
71231014023012
oct213155543564
953205140745
1018685020020
117a19230107
1237556aa358
1319ba126484
14c937c58b2
157455bc365
hex459b6c774

18685020020 has 24 divisors (see below), whose sum is σ = 39241645800. Its totient is φ = 7473416832.

The previous prime is 18685020019. The next prime is 18685020023. The reversal of 18685020020 is 2002058681.

It can be written as a sum of positive squares in 4 ways, for example, as 37478884 + 18647541136 = 6122^2 + 136556^2 .

It is a super-3 number, since 3×186850200203 (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18685020023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 294926 + ... + 352634.

It is an arithmetic number, because the mean of its divisors is an integer number (1635068575).

Almost surely, 218685020020 is an apocalyptic number.

18685020020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18685020020 is an abundant number, since it is smaller than the sum of its proper divisors (20556625780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18685020020 is a wasteful number, since it uses less digits than its factorization.

18685020020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73907 (or 73905 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The spelling of 18685020020 in words is "eighteen billion, six hundred eighty-five million, twenty thousand, twenty".

Divisors: 1 2 4 5 10 20 16189 32378 57709 64756 80945 115418 161890 230836 288545 323780 577090 1154180 934251001 1868502002 3737004004 4671255005 9342510010 18685020020