21687069215 has 32 divisors (see below), whose sum is σ = 30234746880. Its totient is φ = 14626656000.

The previous prime is 21687069163. The next prime is 21687069223. The reversal of 21687069215 is 51296078612.

It is a happy number.

It is not a de Polignac number, because 21687069215 - 2⁸ = 21687068959 is a prime.

It is a super-2 number, since 2×21687069215² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21687069215.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 576740 + ... + 613190.

It is an arithmetic number, because the mean of its divisors is an integer number (944835840).

Almost surely, 2^21687069215 is an apocalyptic number.

21687069215 is a deficient number, since it is larger than the sum of its proper divisors (8547677665).

21687069215 is a wasteful number, since it uses less digits than its factorization.

21687069215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36743.

The product of its (nonzero) digits is 362880, while the sum is 47.

The spelling of 21687069215 in words is "twenty-one billion, six hundred eighty-seven million, sixty-nine thousand, two hundred fifteen".