21231579 has 8 divisors (see below), whose sum is σ = 28349200. Its totient is φ = 14134176.

The previous prime is 21231577. The next prime is 21231583. The reversal of 21231579 is 97513212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21231579 - 2¹ = 21231577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21231577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2404 + ... + 6945.

It is an arithmetic number, because the mean of its divisors is an integer number (3543650).

Almost surely, 2^21231579 is an apocalyptic number.

21231579 is a deficient number, since it is larger than the sum of its proper divisors (7117621).

21231579 is an equidigital number, since it uses as much as digits as its factorization.

21231579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10109.

The product of its digits is 3780, while the sum is 30.

The square root of 21231579 is about 4607.7737574668. The cubic root of 21231579 is about 276.9028535861.

The spelling of 21231579 in words is "twenty-one million, two hundred thirty-one thousand, five hundred seventy-nine".