21325879 has 4 divisors (see below), whose sum is σ = 21336120. Its totient is φ = 21315640.

The previous prime is 21325819. The next prime is 21325891. The reversal of 21325879 is 97852312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21325879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21325819) 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, 757 + ... + 6574.

It is an arithmetic number, because the mean of its divisors is an integer number (5334030).

Almost surely, 2^21325879 is an apocalyptic number.

21325879 is a deficient number, since it is larger than the sum of its proper divisors (10241).

21325879 is an equidigital number, since it uses as much as digits as its factorization.

21325879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10240.

The product of its digits is 30240, while the sum is 37.

The square root of 21325879 is about 4617.9951277584. The cubic root of 21325879 is about 277.3122025641.

The spelling of 21325879 in words is "twenty-one million, three hundred twenty-five thousand, eight hundred seventy-nine".