21579853 has 2 divisors, whose sum is σ = 21579854. Its totient is φ = 21579852.

The previous prime is 21579827. The next prime is 21579913. The reversal of 21579853 is 35897512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20766249 + 813604 = 4557^2 + 902^2 .

It is a cyclic number.

It is not a de Polignac number, because 21579853 - 2⁵ = 21579821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21579053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10789926 + 10789927.

It is an arithmetic number, because the mean of its divisors is an integer number (10789927).

Almost surely, 2^21579853 is an apocalyptic number.

It is an amenable number.

21579853 is a deficient number, since it is larger than the sum of its proper divisors (1).

21579853 is an equidigital number, since it uses as much as digits as its factorization.

21579853 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75600, while the sum is 40.

The square root of 21579853 is about 4645.4120376991. The cubic root of 21579853 is about 278.4087159614.

The spelling of 21579853 in words is "twenty-one million, five hundred seventy-nine thousand, eight hundred fifty-three".