21979542480 has 160 divisors (see below), whose sum is σ = 79527481344. Its totient is φ = 4916986368.

The previous prime is 21979542467. The next prime is 21979542517. The reversal of 21979542480 is 8424597912.

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, 60222 + ... + 218141.

Almost surely, 2^21979542480 is an apocalyptic number.

21979542480 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 21979542480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39763740672).

21979542480 is an abundant number, since it is smaller than the sum of its proper divisors (57547938864).

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

21979542480 is a wasteful number, since it uses less digits than its factorization.

21979542480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278433 (or 278427 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 51.

The spelling of 21979542480 in words is "twenty-one billion, nine hundred seventy-nine million, five hundred forty-two thousand, four hundred eighty".