21765000456 has 64 divisors (see below), whose sum is σ = 61081675200. Its totient is φ = 7180199424.

The previous prime is 21765000437. The next prime is 21765000461. The reversal of 21765000456 is 65400056712.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21765000456.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 498450 + ... + 540353.

It is an arithmetic number, because the mean of its divisors is an integer number (954401175).

Almost surely, 2^21765000456 is an apocalyptic number.

It is an amenable number.

21765000456 is an abundant number, since it is smaller than the sum of its proper divisors (39316674744).

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

21765000456 is a wasteful number, since it uses less digits than its factorization.

21765000456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1038915 (or 1038905 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The spelling of 21765000456 in words is "twenty-one billion, seven hundred sixty-five million, four hundred fifty-six", and thus it is an aban number.