21521625354 has 48 divisors (see below), whose sum is σ = 49413923208. Its totient is φ = 6746305536.

The previous prime is 21521625347. The next prime is 21521625361. The reversal of 21521625354 is 45352612512.

21521625354 is a `hidden beast` number, since 2 + 1 + 5 + 21 + 625 + 3 + 5 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (21521625347) and next prime (21521625361).

It can be written as a sum of positive squares in 4 ways, for example, as 21003835329 + 517790025 = 144927^2 + 22755^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 350094 + ... + 406950.

Almost surely, 2^21521625354 is an apocalyptic number.

21521625354 is an abundant number, since it is smaller than the sum of its proper divisors (27892297854).

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

21521625354 is a wasteful number, since it uses less digits than its factorization.

21521625354 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58119 (or 58116 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The spelling of 21521625354 in words is "twenty-one billion, five hundred twenty-one million, six hundred twenty-five thousand, three hundred fifty-four".