21897729479824 has 40 divisors (see below), whose sum is σ = 46637149093920. Its totient is φ = 9877532371200.

The previous prime is 21897729479737. The next prime is 21897729479837. The reversal of 21897729479824 is 42897492779812.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 474858309 + ... + 474904420.

It is an arithmetic number, because the mean of its divisors is an integer number (1165928727348).

Almost surely, 2^{21897729479824} is an apocalyptic number.

It is an amenable number.

21897729479824 is an abundant number, since it is smaller than the sum of its proper divisors (24739419614096).

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

21897729479824 is a wasteful number, since it uses less digits than its factorization.

21897729479824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 949762879 (or 949762873 counting only the distinct ones).

The product of its digits is 2048385024, while the sum is 79.

The spelling of 21897729479824 in words is "twenty-one trillion, eight hundred ninety-seven billion, seven hundred twenty-nine million, four hundred seventy-nine thousand, eight hundred twenty-four".