21679079 has 4 divisors (see below), whose sum is σ = 22140384. Its totient is φ = 21217776.

The previous prime is 21679051. The next prime is 21679081. The reversal of 21679079 is 97097612.

It is a happy number.

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 21679079 - 2⁸ = 21678823 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21679039) 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, 230582 + ... + 230675.

It is an arithmetic number, because the mean of its divisors is an integer number (5535096).

Almost surely, 2^21679079 is an apocalyptic number.

21679079 is a deficient number, since it is larger than the sum of its proper divisors (461305).

21679079 is an equidigital number, since it uses as much as digits as its factorization.

21679079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461304.

The product of its (nonzero) digits is 47628, while the sum is 41.

The square root of 21679079 is about 4656.0797888352. The cubic root of 21679079 is about 278.8347792559.

The spelling of 21679079 in words is "twenty-one million, six hundred seventy-nine thousand, seventy-nine".