21758478364 has 24 divisors (see below), whose sum is σ = 46076778720. Its totient is φ = 8776528896.

The previous prime is 21758478359. The next prime is 21758478373. The reversal of 21758478364 is 46387485712.

It is a super-2 number, since 2×21758478364² (a number of 21 digits) contains 22 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 (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22855069 + ... + 22856020.

It is an arithmetic number, because the mean of its divisors is an integer number (1919865780).

Almost surely, 2^21758478364 is an apocalyptic number.

It is an amenable number.

21758478364 is an abundant number, since it is smaller than the sum of its proper divisors (24318300356).

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

21758478364 is a wasteful number, since it uses less digits than its factorization.

21758478364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45711117 (or 45711115 counting only the distinct ones).

The product of its digits is 9031680, while the sum is 55.

The spelling of 21758478364 in words is "twenty-one billion, seven hundred fifty-eight million, four hundred seventy-eight thousand, three hundred sixty-four".