21256080287 has 12 divisors (see below), whose sum is σ = 23126062824. Its totient is φ = 19527973920.

The previous prime is 21256080281. The next prime is 21256080301. The reversal of 21256080287 is 78208065212.

It is not a de Polignac number, because 21256080287 - 2²² = 21251885983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21256080281) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 262388 + ... + 333705.

It is an arithmetic number, because the mean of its divisors is an integer number (1927171902).

Almost surely, 2^21256080287 is an apocalyptic number.

21256080287 is a deficient number, since it is larger than the sum of its proper divisors (1869982537).

21256080287 is a wasteful number, since it uses less digits than its factorization.

21256080287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 596330 (or 596317 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 41.

The spelling of 21256080287 in words is "twenty-one billion, two hundred fifty-six million, eighty thousand, two hundred eighty-seven".