21464177920 has 72 divisors (see below), whose sum is σ = 51548829696. Its totient is φ = 8563058688.

The previous prime is 21464177893. The next prime is 21464177941. The reversal of 21464177920 is 2977146412.

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 7 ways as a sum of consecutive naturals, for example, 468349 + ... + 512131.

It is an arithmetic number, because the mean of its divisors is an integer number (715955968).

Almost surely, 2^21464177920 is an apocalyptic number.

21464177920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21464177920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25774414848).

21464177920 is an abundant number, since it is smaller than the sum of its proper divisors (30084651776).

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

21464177920 is an equidigital number, since it uses as much as digits as its factorization.

21464177920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44187 (or 44173 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 43.

The spelling of 21464177920 in words is "twenty-one billion, four hundred sixty-four million, one hundred seventy-seven thousand, nine hundred twenty".