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21128970240 = 21532572389
BaseRepresentation
bin10011101011011000…
…101000000000000000
32000112111212220021100
4103223120220000000
5321233004021430
613412335054400
71345411166220
oct235330500000
960474786240
1021128970240
118a62831084
124118071400
131cb955c971
141046206080
15839e25960
hex4eb628000

21128970240 has 768 divisors, whose sum is σ = 88330694400. Its totient is φ = 4567597056.

The previous prime is 21128970229. The next prime is 21128970253. The reversal of 21128970240 is 4207982112.

It is a tau number, because it is divible by the number of its divisors (768).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21128970195 and 21128970204.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 237404116 + ... + 237404204.

It is an arithmetic number, because the mean of its divisors is an integer number (115013925).

Almost surely, 221128970240 is an apocalyptic number.

21128970240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21128970240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44165347200).

21128970240 is an abundant number, since it is smaller than the sum of its proper divisors (67201724160).

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

21128970240 is an equidigital number, since it uses as much as digits as its factorization.

21128970240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160 (or 129 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The spelling of 21128970240 in words is "twenty-one billion, one hundred twenty-eight million, nine hundred seventy thousand, two hundred forty".