21554512052 has 6 divisors (see below), whose sum is σ = 37720396098. Its totient is φ = 10777256024.

The previous prime is 21554512039. The next prime is 21554512061. The reversal of 21554512052 is 25021545512.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19014755236 + 2539756816 = 137894^2 + 50396^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2694314003 + ... + 2694314010.

It is an arithmetic number, because the mean of its divisors is an integer number (6286732683).

Almost surely, 2^21554512052 is an apocalyptic number.

It is an amenable number.

21554512052 is a deficient number, since it is larger than the sum of its proper divisors (16165884046).

21554512052 is a wasteful number, since it uses less digits than its factorization.

21554512052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5388628017 (or 5388628015 counting only the distinct ones).

The product of its (nonzero) digits is 20000, while the sum is 32.

The spelling of 21554512052 in words is "twenty-one billion, five hundred fifty-four million, five hundred twelve thousand, fifty-two".