21613553460 has 48 divisors (see below), whose sum is σ = 67242168000. Its totient is φ = 5763614112.

The previous prime is 21613553453. The next prime is 21613553503. The reversal of 21613553460 is 6435531612.

21613553460 is a `hidden beast` number, since 2 + 1 + 61 + 3 + 5 + 534 + 60 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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 15 ways as a sum of consecutive naturals, for example, 20012010 + ... + 20013089.

It is an arithmetic number, because the mean of its divisors is an integer number (1400878500).

Almost surely, 2^21613553460 is an apocalyptic number.

21613553460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21613553460 is an abundant number, since it is smaller than the sum of its proper divisors (45628614540).

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

21613553460 is a wasteful number, since it uses less digits than its factorization.

21613553460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40025117 (or 40025109 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 21613553460 in words is "twenty-one billion, six hundred thirteen million, five hundred fifty-three thousand, four hundred sixty".