21307520775 has 48 divisors (see below), whose sum is σ = 37342922400. Its totient is φ = 10683432960.

The previous prime is 21307520753. The next prime is 21307520837. The reversal of 21307520775 is 57702570312.

It is not a de Polignac number, because 21307520775 - 2²⁰ = 21306472199 is a prime.

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 47 ways as a sum of consecutive naturals, for example, 1175481 + ... + 1193469.

It is an arithmetic number, because the mean of its divisors is an integer number (777977550).

Almost surely, 2^21307520775 is an apocalyptic number.

21307520775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21307520775 is a deficient number, since it is larger than the sum of its proper divisors (16035401625).

21307520775 is a wasteful number, since it uses less digits than its factorization.

21307520775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18948 (or 18943 counting only the distinct ones).

The product of its (nonzero) digits is 102900, while the sum is 39.

The spelling of 21307520775 in words is "twenty-one billion, three hundred seven million, five hundred twenty thousand, seven hundred seventy-five".