21664035450 has 36 divisors (see below), whose sum is σ = 58204043118. Its totient is φ = 5777076000.

The previous prime is 21664035433. The next prime is 21664035473. The reversal of 21664035450 is 5453046612.

21664035450 is a `hidden beast` number, since 2 + 1 + 6 + 640 + 3 + 5 + 4 + 5 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 8356336569 + 13307698881 = 91413^2 + 115359^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 24070701 + ... + 24071600.

Almost surely, 2^21664035450 is an apocalyptic number.

21664035450 is an abundant number, since it is smaller than the sum of its proper divisors (36540007668).

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

21664035450 is a wasteful number, since it uses less digits than its factorization.

21664035450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48142319 (or 48142311 counting only the distinct ones).

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

The spelling of 21664035450 in words is "twenty-one billion, six hundred sixty-four million, thirty-five thousand, four hundred fifty".