21563135874 has 40 divisors (see below), whose sum is σ = 55219885248. Its totient is φ = 6160895640.

The previous prime is 21563135831. The next prime is 21563135941. The reversal of 21563135874 is 47853136512.

It is a happy number.

21563135874 is a `hidden beast` number, since 2 + 1 + 5 + 63 + 1 + 3 + 587 + 4 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9506422 + ... + 9508689.

Almost surely, 2^21563135874 is an apocalyptic number.

21563135874 is an abundant number, since it is smaller than the sum of its proper divisors (33656749374).

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

21563135874 is a wasteful number, since it uses less digits than its factorization.

21563135874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19015132 (or 19015123 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The spelling of 21563135874 in words is "twenty-one billion, five hundred sixty-three million, one hundred thirty-five thousand, eight hundred seventy-four".