21577745384 has 32 divisors (see below), whose sum is σ = 43586401320. Its totient is φ = 9955312896.

The previous prime is 21577745377. The next prime is 21577745459. The reversal of 21577745384 is 48354777512.

It can be written as a sum of positive squares in 4 ways, for example, as 11653202500 + 9924542884 = 107950^2 + 99622^2 .

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 7 ways as a sum of consecutive naturals, for example, 258482 + ... + 331614.

Almost surely, 2^21577745384 is an apocalyptic number.

It is an amenable number.

21577745384 is an abundant number, since it is smaller than the sum of its proper divisors (22008655936).

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

21577745384 is a wasteful number, since it uses less digits than its factorization.

21577745384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75989 (or 75985 counting only the distinct ones).

The product of its digits is 6585600, while the sum is 53.

The spelling of 21577745384 in words is "twenty-one billion, five hundred seventy-seven million, seven hundred forty-five thousand, three hundred eighty-four".