21179359 has 4 divisors (see below), whose sum is σ = 21434616. Its totient is φ = 20924104.

The previous prime is 21179351. The next prime is 21179363. The reversal of 21179359 is 95397112.

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 21179359 - 2³ = 21179351 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 (21179351) 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, 127504 + ... + 127669.

It is an arithmetic number, because the mean of its divisors is an integer number (5358654).

Almost surely, 2^21179359 is an apocalyptic number.

21179359 is a deficient number, since it is larger than the sum of its proper divisors (255257).

21179359 is an equidigital number, since it uses as much as digits as its factorization.

21179359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255256.

The product of its digits is 17010, while the sum is 37.

The square root of 21179359 is about 4602.1037580654. The cubic root of 21179359 is about 276.6756489721.

It can be divided in two parts, 2117 and 9359, that added together give a triangular number (11476 = T₁₅₁).

The spelling of 21179359 in words is "twenty-one million, one hundred seventy-nine thousand, three hundred fifty-nine".