20667979 has 8 divisors (see below), whose sum is σ = 21629312. Its totient is φ = 19725120.

The previous prime is 20667973. The next prime is 20668027. The reversal of 20667979 is 97976602.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20667979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20667973) 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, 2304 + ... + 6829.

It is an arithmetic number, because the mean of its divisors is an integer number (2703664).

Almost surely, 2^20667979 is an apocalyptic number.

20667979 is a deficient number, since it is larger than the sum of its proper divisors (961333).

20667979 is an equidigital number, since it uses as much as digits as its factorization.

20667979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9237.

The product of its (nonzero) digits is 285768, while the sum is 46.

The square root of 20667979 is about 4546.2049007936. The cubic root of 20667979 is about 274.4306855599.

The spelling of 20667979 in words is "twenty million, six hundred sixty-seven thousand, nine hundred seventy-nine".