21869290856 has 32 divisors (see below), whose sum is σ = 47427387840. Its totient is φ = 9259628928.

The previous prime is 21869290853. The next prime is 21869290889. The reversal of 21869290856 is 65809296812.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is not an unprimeable number, because it can be changed into a prime (21869290853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2347901 + ... + 2357196.

It is an arithmetic number, because the mean of its divisors is an integer number (1482105870).

Almost surely, 2^21869290856 is an apocalyptic number.

It is an amenable number.

21869290856 is an abundant number, since it is smaller than the sum of its proper divisors (25558096984).

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

21869290856 is a wasteful number, since it uses less digits than its factorization.

21869290856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4705193 (or 4705189 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 56.

The spelling of 21869290856 in words is "twenty-one billion, eight hundred sixty-nine million, two hundred ninety thousand, eight hundred fifty-six".