20689679 has 8 divisors (see below), whose sum is σ = 21450240. Its totient is φ = 19935000.

The previous prime is 20689661. The next prime is 20689699. The reversal of 20689679 is 97698602.

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 20689679 - 2²⁴ = 3912463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20689619) 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, 6452 + ... + 9110.

It is an arithmetic number, because the mean of its divisors is an integer number (2681280).

Almost surely, 2^20689679 is an apocalyptic number.

20689679 is a deficient number, since it is larger than the sum of its proper divisors (760561).

20689679 is a wasteful number, since it uses less digits than its factorization.

20689679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2941.

The product of its (nonzero) digits is 326592, while the sum is 47.

The square root of 20689679 is about 4548.5908807014. The cubic root of 20689679 is about 274.5266966071.

The spelling of 20689679 in words is "twenty million, six hundred eighty-nine thousand, six hundred seventy-nine".