21533863588 has 12 divisors (see below), whose sum is σ = 37690920540. Its totient is φ = 10765029152.

The previous prime is 21533863553. The next prime is 21533863649. The reversal of 21533863588 is 88536833512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 2035092544 + 19498771044 = 45112^2 + 139638^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 450043 + ... + 495586.

It is an arithmetic number, because the mean of its divisors is an integer number (3140910045).

Almost surely, 2^21533863588 is an apocalyptic number.

It is an amenable number.

21533863588 is a deficient number, since it is larger than the sum of its proper divisors (16157056952).

21533863588 is a wasteful number, since it uses less digits than its factorization.

21533863588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951326 (or 951324 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 52.

The spelling of 21533863588 in words is "twenty-one billion, five hundred thirty-three million, eight hundred sixty-three thousand, five hundred eighty-eight".