21106579 has 10 divisors (see below), whose sum is σ = 22896340. Its totient is φ = 19456632.

The previous prime is 21106573. The next prime is 21106583. The reversal of 21106579 is 97560112.

It is not a de Polignac number, because 21106579 - 2⁹ = 21106067 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 21106579.

It is not an unprimeable number, because it can be changed into a prime (21106573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 28192 + ... + 28930.

It is an arithmetic number, because the mean of its divisors is an integer number (2289634).

Almost surely, 2^21106579 is an apocalyptic number.

21106579 is a deficient number, since it is larger than the sum of its proper divisors (1789761).

21106579 is an frugal number, since it uses more digits than its factorization.

21106579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791 (or 752 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 21106579 is about 4594.1897000450. The cubic root of 21106579 is about 276.3583657898.

The spelling of 21106579 in words is "twenty-one million, one hundred six thousand, five hundred seventy-nine".