21553435504 has 20 divisors (see below), whose sum is σ = 41825981200. Its totient is φ = 10759633920.

The previous prime is 21553435487. The next prime is 21553435507. The reversal of 21553435504 is 40553435512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21553435507) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1057329 + ... + 1077520.

It is an arithmetic number, because the mean of its divisors is an integer number (2091299060).

Almost surely, 2^21553435504 is an apocalyptic number.

It is an amenable number.

21553435504 is a deficient number, since it is larger than the sum of its proper divisors (20272545696).

21553435504 is a wasteful number, since it uses less digits than its factorization.

21553435504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135488 (or 2135482 counting only the distinct ones).

The product of its (nonzero) digits is 180000, while the sum is 37.

The spelling of 21553435504 in words is "twenty-one billion, five hundred fifty-three million, four hundred thirty-five thousand, five hundred four".