21405915027 has 12 divisors (see below), whose sum is σ = 35336748720. Its totient is φ = 12231951408.

The previous prime is 21405915001. The next prime is 21405915107. The reversal of 21405915027 is 72051950412.

21405915027 is a `hidden beast` number, since 2 + 1 + 40 + 591 + 5 + 0 + 27 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21405915027 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21405914982 and 21405915000.

It is not an unprimeable number, because it can be changed into a prime (21405955027) 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, 169888152 + ... + 169888277.

It is an arithmetic number, because the mean of its divisors is an integer number (2944729060).

Almost surely, 2^21405915027 is an apocalyptic number.

21405915027 is a deficient number, since it is larger than the sum of its proper divisors (13930833693).

21405915027 is a wasteful number, since it uses less digits than its factorization.

21405915027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339776442 (or 339776439 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The spelling of 21405915027 in words is "twenty-one billion, four hundred five million, nine hundred fifteen thousand, twenty-seven".