21132279 has 24 divisors (see below), whose sum is σ = 36420720. Its totient is φ = 12074832.

The previous prime is 21132277. The next prime is 21132289. The reversal of 21132279 is 97223112.

It is not a de Polignac number, because 21132279 - 2¹ = 21132277 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132277) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6664 + ... + 9309.

It is an arithmetic number, because the mean of its divisors is an integer number (1517530).

Almost surely, 2^21132279 is an apocalyptic number.

21132279 is a deficient number, since it is larger than the sum of its proper divisors (15288441).

21132279 is a wasteful number, since it uses less digits than its factorization.

21132279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15996 (or 15983 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 21132279 is about 4596.9858603220. The cubic root of 21132279 is about 276.4704876903.

The spelling of 21132279 in words is "twenty-one million, one hundred thirty-two thousand, two hundred seventy-nine".