21327972 has 48 divisors (see below), whose sum is σ = 51170112. Its totient is φ = 6912000.

The previous prime is 21327961. The next prime is 21327973. The reversal of 21327972 is 27972312.

It is not an unprimeable number, because it can be changed into a prime (21327973) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84847 + ... + 85097.

It is an arithmetic number, because the mean of its divisors is an integer number (1066044).

Almost surely, 2^21327972 is an apocalyptic number.

It is an amenable number.

21327972 is an abundant number, since it is smaller than the sum of its proper divisors (29842140).

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

21327972 is a wasteful number, since it uses less digits than its factorization.

21327972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428 (or 426 counting only the distinct ones).

The product of its digits is 10584, while the sum is 33.

The square root of 21327972 is about 4618.2217356900. The cubic root of 21327972 is about 277.3212744130.

The spelling of 21327972 in words is "twenty-one million, three hundred twenty-seven thousand, nine hundred seventy-two".