21679031 has 8 divisors (see below), whose sum is σ = 23802384. Its totient is φ = 19581120.

The previous prime is 21679001. The next prime is 21679033. The reversal of 21679031 is 13097612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21679031 - 2⁶ = 21678967 is a prime.

It is a super-2 number, since 2×21679031² = 939960770197922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21678985 and 21679003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21679033) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4550 + ... + 8003.

It is an arithmetic number, because the mean of its divisors is an integer number (2975298).

Almost surely, 2^21679031 is an apocalyptic number.

21679031 is a deficient number, since it is larger than the sum of its proper divisors (2123353).

21679031 is a wasteful number, since it uses less digits than its factorization.

21679031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12721.

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 21679031 is about 4656.0746342815. The cubic root of 21679031 is about 278.8345734649.

The spelling of 21679031 in words is "twenty-one million, six hundred seventy-nine thousand, thirty-one".