21086310078 has 12 divisors (see below), whose sum is σ = 45687005208. Its totient is φ = 7028770020.

The previous prime is 21086310059. The next prime is 21086310097. The reversal of 21086310078 is 87001368012.

21086310078 is a `hidden beast` number, since 2 + 10 + 8 + 631 + 0 + 0 + 7 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (21086310059) and next prime (21086310097).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 585730818 + ... + 585730853.

It is an arithmetic number, because the mean of its divisors is an integer number (3807250434).

Almost surely, 2^21086310078 is an apocalyptic number.

21086310078 is an abundant number, since it is smaller than the sum of its proper divisors (24600695130).

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

21086310078 is a wasteful number, since it uses less digits than its factorization.

21086310078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1171461679 (or 1171461676 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The spelling of 21086310078 in words is "twenty-one billion, eighty-six million, three hundred ten thousand, seventy-eight".