21608079 has 4 divisors (see below), whose sum is σ = 28810776. Its totient is φ = 14405384.

The previous prime is 21608077. The next prime is 21608089. The reversal of 21608079 is 97080612.

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 21608079 - 2¹ = 21608077 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21608077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3601344 + ... + 3601349.

It is an arithmetic number, because the mean of its divisors is an integer number (7202694).

Almost surely, 2^21608079 is an apocalyptic number.

21608079 is a deficient number, since it is larger than the sum of its proper divisors (7202697).

21608079 is an equidigital number, since it uses as much as digits as its factorization.

21608079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7202696.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 21608079 is about 4648.4490962040. The cubic root of 21608079 is about 278.5300473518.

The spelling of 21608079 in words is "twenty-one million, six hundred eight thousand, seventy-nine".