21421531272 has 32 divisors (see below), whose sum is σ = 53559921600. Its totient is φ = 7139697984.

The previous prime is 21421531213. The next prime is 21421531273. The reversal of 21421531272 is 27213512412.

It is not an unprimeable number, because it can be changed into a prime (21421531273) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187338 + ... + 279174.

It is an arithmetic number, because the mean of its divisors is an integer number (1673747550).

Almost surely, 2^21421531272 is an apocalyptic number.

It is an amenable number.

21421531272 is an abundant number, since it is smaller than the sum of its proper divisors (32138390328).

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

21421531272 is a wasteful number, since it uses less digits than its factorization.

21421531272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101565 (or 101561 counting only the distinct ones).

The product of its digits is 6720, while the sum is 30.

The spelling of 21421531272 in words is "twenty-one billion, four hundred twenty-one million, five hundred thirty-one thousand, two hundred seventy-two".