21858957956 has 48 divisors (see below), whose sum is σ = 44127659520. Its totient is φ = 9380832000.

The previous prime is 21858957943. The next prime is 21858958007. The reversal of 21858957956 is 65975985812.

It is a super-3 number, since 3×21858957956³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21858957892 and 21858957901.

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, 139511 + ... + 251358.

It is an arithmetic number, because the mean of its divisors is an integer number (919326240).

Almost surely, 2^21858957956 is an apocalyptic number.

It is an amenable number.

21858957956 is an abundant number, since it is smaller than the sum of its proper divisors (22268701564).

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

21858957956 is a wasteful number, since it uses less digits than its factorization.

21858957956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390956 (or 390954 counting only the distinct ones).

The product of its digits is 54432000, while the sum is 65.

The spelling of 21858957956 in words is "twenty-one billion, eight hundred fifty-eight million, nine hundred fifty-seven thousand, nine hundred fifty-six".