21579373 has 2 divisors, whose sum is σ = 21579374. Its totient is φ = 21579372.

The previous prime is 21579367. The next prime is 21579377. The reversal of 21579373 is 37397512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13638249 + 7941124 = 3693^2 + 2818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21579373 - 2⁹ = 21578861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21579377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10789686 + 10789687.

It is an arithmetic number, because the mean of its divisors is an integer number (10789687).

Almost surely, 2^21579373 is an apocalyptic number.

It is an amenable number.

21579373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21579373 is an equidigital number, since it uses as much as digits as its factorization.

21579373 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39690, while the sum is 37.

The square root of 21579373 is about 4645.3603735340. The cubic root of 21579373 is about 278.4066517339.

It can be divided in two parts, 21579 and 373, that added together give a cube (21952 = 28³).

The spelling of 21579373 in words is "twenty-one million, five hundred seventy-nine thousand, three hundred seventy-three".