21279672 has 40 divisors (see below), whose sum is σ = 59604600. Its totient is φ = 7093008.

The previous prime is 21279653. The next prime is 21279679. The reversal of 21279672 is 27697212.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21279679) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 15772 + ... + 17067.

It is an arithmetic number, because the mean of its divisors is an integer number (1490115).

Almost surely, 2^21279672 is an apocalyptic number.

It is an amenable number.

21279672 is an abundant number, since it is smaller than the sum of its proper divisors (38324928).

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

21279672 is a wasteful number, since it uses less digits than its factorization.

21279672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32857 (or 32844 counting only the distinct ones).

The product of its digits is 21168, while the sum is 36.

The square root of 21279672 is about 4612.9894862226. The cubic root of 21279672 is about 277.1117726753. Note that the first 3 decimals are identical.

The spelling of 21279672 in words is "twenty-one million, two hundred seventy-nine thousand, six hundred seventy-two".