21535553552 has 20 divisors (see below), whose sum is σ = 42155294076. Its totient is φ = 10656768000.

The previous prime is 21535553509. The next prime is 21535553617. The reversal of 21535553552 is 25535553512.

It can be written as a sum of positive squares in 2 ways, for example, as 5703874576 + 15831678976 = 75524^2 + 125824^2 .

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, 6936449 + ... + 6939552.

Almost surely, 2^21535553552 is an apocalyptic number.

It is an amenable number.

21535553552 is a deficient number, since it is larger than the sum of its proper divisors (20619740524).

21535553552 is a wasteful number, since it uses less digits than its factorization.

21535553552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13876106 (or 13876100 counting only the distinct ones).

The product of its digits is 562500, while the sum is 41.

The spelling of 21535553552 in words is "twenty-one billion, five hundred thirty-five million, five hundred fifty-three thousand, five hundred fifty-two".