21578992380 has 576 divisors, whose sum is σ = 78379176960. Its totient is φ = 4914961920.

The previous prime is 21578992373. The next prime is 21578992427. The reversal of 21578992380 is 8329987512.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 124733974 + ... + 124734146.

It is an arithmetic number, because the mean of its divisors is an integer number (136074960).

Almost surely, 2^21578992380 is an apocalyptic number.

21578992380 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 21578992380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39189588480).

21578992380 is an abundant number, since it is smaller than the sum of its proper divisors (56800184580).

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

21578992380 is a wasteful number, since it uses less digits than its factorization.

21578992380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The spelling of 21578992380 in words is "twenty-one billion, five hundred seventy-eight million, nine hundred ninety-two thousand, three hundred eighty".