21379013880 has 128 divisors (see below), whose sum is σ = 73406062080. Its totient is φ = 4879526400.

The previous prime is 21379013839. The next prime is 21379013893. The reversal of 21379013880 is 8831097312.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 570687 + ... + 606993.

It is an arithmetic number, because the mean of its divisors is an integer number (573484860).

Almost surely, 2^21379013880 is an apocalyptic number.

21379013880 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 21379013880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36703031040).

21379013880 is an abundant number, since it is smaller than the sum of its proper divisors (52027048200).

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

21379013880 is a wasteful number, since it uses less digits than its factorization.

21379013880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37029 (or 37025 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 42.

The spelling of 21379013880 in words is "twenty-one billion, three hundred seventy-nine million, thirteen thousand, eight hundred eighty".