21606532425 has 36 divisors (see below), whose sum is σ = 38709176844. Its totient is φ = 11520662400.

The previous prime is 21606532417. The next prime is 21606532433. The reversal of 21606532425 is 52423560612.

21606532425 is a `hidden beast` number, since 2 + 1 + 606 + 5 + 3 + 2 + 42 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (21606532417) and next prime (21606532433).

It can be written as a sum of positive squares in 6 ways, for example, as 2984109129 + 18622423296 = 54627^2 + 136464^2 .

It is not a de Polignac number, because 21606532425 - 2³ = 21606532417 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21606532425.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1174599 + ... + 1192851.

Almost surely, 2^21606532425 is an apocalyptic number.

21606532425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21606532425 is a deficient number, since it is larger than the sum of its proper divisors (17102644419).

21606532425 is a wasteful number, since it uses less digits than its factorization.

21606532425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23530 (or 23522 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The spelling of 21606532425 in words is "twenty-one billion, six hundred six million, five hundred thirty-two thousand, four hundred twenty-five".