21368429972 has 12 divisors (see below), whose sum is σ = 38100314196. Its totient is φ = 10482625920.

The previous prime is 21368429969. The next prime is 21368429993. The reversal of 21368429972 is 27992486312.

It can be written as a sum of positive squares in 2 ways, for example, as 6621727876 + 14746702096 = 81374^2 + 121436^2 .

It is a Harshad number since it is a multiple of its sum of digits (53).

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, 50397029 + ... + 50397452.

It is an arithmetic number, because the mean of its divisors is an integer number (3175026183).

Almost surely, 2^21368429972 is an apocalyptic number.

It is an amenable number.

21368429972 is a deficient number, since it is larger than the sum of its proper divisors (16731884224).

21368429972 is a wasteful number, since it uses less digits than its factorization.

21368429972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100794538 (or 100794536 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 53.

The spelling of 21368429972 in words is "twenty-one billion, three hundred sixty-eight million, four hundred twenty-nine thousand, nine hundred seventy-two".