21758393364 has 96 divisors (see below), whose sum is σ = 55442128896. Its totient is φ = 6614576640.

The previous prime is 21758393329. The next prime is 21758393413. The reversal of 21758393364 is 46339385712.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1104279 + ... + 1123809.

It is an arithmetic number, because the mean of its divisors is an integer number (577522176).

Almost surely, 2^21758393364 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21758393364, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27721064448).

21758393364 is an abundant number, since it is smaller than the sum of its proper divisors (33683735532).

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

21758393364 is a wasteful number, since it uses less digits than its factorization.

21758393364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19725 (or 19723 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 51.

The spelling of 21758393364 in words is "twenty-one billion, seven hundred fifty-eight million, three hundred ninety-three thousand, three hundred sixty-four".