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18905020 = 2251755603
BaseRepresentation
bin100100000011…
…1011110111100
31022120110210221
41020013132330
514314430040
61513111124
7316455451
oct110073674
938513727
1018905020
11a742692
1263b84a4
133bbbc04
142721828
1519d674a
hex12077bc

18905020 has 24 divisors (see below), whose sum is σ = 42036624. Its totient is φ = 7117056.

The previous prime is 18905017. The next prime is 18905021. The reversal of 18905020 is 2050981.

18905020 = T624 + T625 + ... + T708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18905021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27462 + ... + 28141.

It is an arithmetic number, because the mean of its divisors is an integer number (1751526).

Almost surely, 218905020 is an apocalyptic number.

18905020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18905020 is an abundant number, since it is smaller than the sum of its proper divisors (23131604).

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

18905020 is a wasteful number, since it uses less digits than its factorization.

18905020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55629 (or 55627 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 18905020 is about 4347.9903403757. The cubic root of 18905020 is about 266.3947819170.

The spelling of 18905020 in words is "eighteen million, nine hundred five thousand, twenty".

Divisors: 1 2 4 5 10 17 20 34 68 85 170 340 55603 111206 222412 278015 556030 945251 1112060 1890502 3781004 4726255 9452510 18905020