21607679 has 2 divisors, whose sum is σ = 21607680. Its totient is φ = 21607678.

The previous prime is 21607673. The next prime is 21607709. The reversal of 21607679 is 97670612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21607679 is a prime.

It is a Chen prime.

It is equal to p_1365977 and since 21607679 and 1365977 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21607673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10803839 + 10803840.

It is an arithmetic number, because the mean of its divisors is an integer number (10803840).

Almost surely, 2^21607679 is an apocalyptic number.

21607679 is a deficient number, since it is larger than the sum of its proper divisors (1).

21607679 is an equidigital number, since it uses as much as digits as its factorization.

21607679 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 21607679 is about 4648.4060709022. The cubic root of 21607679 is about 278.5283286628.

The spelling of 21607679 in words is "twenty-one million, six hundred seven thousand, six hundred seventy-nine".