21322579 has 4 divisors (see below), whose sum is σ = 22444840. Its totient is φ = 20200320.

The previous prime is 21322571. The next prime is 21322601. The reversal of 21322579 is 97522312.

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 21322579 - 2³ = 21322571 is a prime.

It is a super-2 number, since 2×21322579² = 909304750422482, which contains 22 as substring.

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 21322579.

It is not an unprimeable number, because it can be changed into a prime (21322571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561102 + ... + 561139.

It is an arithmetic number, because the mean of its divisors is an integer number (5611210).

Almost surely, 2^21322579 is an apocalyptic number.

21322579 is a deficient number, since it is larger than the sum of its proper divisors (1122261).

21322579 is a wasteful number, since it uses less digits than its factorization.

21322579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1122260.

The product of its digits is 7560, while the sum is 31.

The square root of 21322579 is about 4617.6378160267. The cubic root of 21322579 is about 277.2978979177.

The spelling of 21322579 in words is "twenty-one million, three hundred twenty-two thousand, five hundred seventy-nine".