21797409372 has 12 divisors (see below), whose sum is σ = 50860621896. Its totient is φ = 7265803120.

The previous prime is 21797409353. The next prime is 21797409391. The reversal of 21797409372 is 27390479712.

It is an interprime number because it is at equal distance from previous prime (21797409353) and next prime (21797409391).

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 908225379 + ... + 908225402.

It is an arithmetic number, because the mean of its divisors is an integer number (4238385158).

Almost surely, 2^21797409372 is an apocalyptic number.

It is an amenable number.

21797409372 is an abundant number, since it is smaller than the sum of its proper divisors (29063212524).

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

21797409372 is a wasteful number, since it uses less digits than its factorization.

21797409372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1816450788 (or 1816450786 counting only the distinct ones).

The product of its (nonzero) digits is 1333584, while the sum is 51.

The spelling of 21797409372 in words is "twenty-one billion, seven hundred ninety-seven million, four hundred nine thousand, three hundred seventy-two".