21156894892 has 48 divisors (see below), whose sum is σ = 42589048320. Its totient is φ = 9008433792.

The previous prime is 21156894887. The next prime is 21156894919. The reversal of 21156894892 is 29849865112.

It is a super-2 number, since 2×21156894892² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3173859 + ... + 3180517.

It is an arithmetic number, because the mean of its divisors is an integer number (887271840).

Almost surely, 2^21156894892 is an apocalyptic number.

It is an amenable number.

21156894892 is an abundant number, since it is smaller than the sum of its proper divisors (21432153428).

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

21156894892 is a wasteful number, since it uses less digits than its factorization.

21156894892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7390 (or 7388 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 55.

The spelling of 21156894892 in words is "twenty-one billion, one hundred fifty-six million, eight hundred ninety-four thousand, eight hundred ninety-two".