21453605556 has 96 divisors (see below), whose sum is σ = 51559710720. Its totient is φ = 6940733184.

The previous prime is 21453605539. The next prime is 21453605581. The reversal of 21453605556 is 65550635412.

It is a super-3 number, since 3×21453605556³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16642960 + ... + 16644248.

It is an arithmetic number, because the mean of its divisors is an integer number (537080320).

Almost surely, 2^21453605556 is an apocalyptic number.

It is an amenable number.

21453605556 is an abundant number, since it is smaller than the sum of its proper divisors (30106105164).

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

21453605556 is a wasteful number, since it uses less digits than its factorization.

21453605556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1653 (or 1651 counting only the distinct ones).

The product of its (nonzero) digits is 540000, while the sum is 42.

The spelling of 21453605556 in words is "twenty-one billion, four hundred fifty-three million, six hundred five thousand, five hundred fifty-six".