21653261400 has 48 divisors (see below), whose sum is σ = 67125112200. Its totient is φ = 5774202880.

The previous prime is 21653261359. The next prime is 21653261419. The reversal of 21653261400 is 416235612.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18043785 + ... + 18044984.

Almost surely, 2^21653261400 is an apocalyptic number.

21653261400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21653261400 is an abundant number, since it is smaller than the sum of its proper divisors (45471850800).

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

21653261400 is a wasteful number, since it uses less digits than its factorization.

21653261400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36088788 (or 36088779 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The spelling of 21653261400 in words is "twenty-one billion, six hundred fifty-three million, two hundred sixty-one thousand, four hundred".