21132679 has 4 divisors (see below), whose sum is σ = 21490920. Its totient is φ = 20774440.

The previous prime is 21132667. The next prime is 21132689. The reversal of 21132679 is 97623112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21132679 - 2¹³ = 21124487 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21132679.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179032 + ... + 179149.

It is an arithmetic number, because the mean of its divisors is an integer number (5372730).

Almost surely, 2^21132679 is an apocalyptic number.

21132679 is a deficient number, since it is larger than the sum of its proper divisors (358241).

21132679 is an equidigital number, since it uses as much as digits as its factorization.

21132679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358240.

The product of its digits is 4536, while the sum is 31.

The square root of 21132679 is about 4597.0293668847. The cubic root of 21132679 is about 276.4722320596.

The spelling of 21132679 in words is "twenty-one million, one hundred thirty-two thousand, six hundred seventy-nine".