21178969580 has 48 divisors (see below), whose sum is σ = 47462962176. Its totient is φ = 7910461440.

The previous prime is 21178969543. The next prime is 21178969607. The reversal of 21178969580 is 8596987112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 202061 + ... + 288420.

It is an arithmetic number, because the mean of its divisors is an integer number (988811712).

Almost surely, 2^21178969580 is an apocalyptic number.

21178969580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21178969580 is an abundant number, since it is smaller than the sum of its proper divisors (26283992596).

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

21178969580 is a wasteful number, since it uses less digits than its factorization.

21178969580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490634 (or 490632 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 56.

The spelling of 21178969580 in words is "twenty-one billion, one hundred seventy-eight million, nine hundred sixty-nine thousand, five hundred eighty".