20634979 has 8 divisors (see below), whose sum is σ = 22275360. Its totient is φ = 19056576.

The previous prime is 20634959. The next prime is 20634997. The reversal of 20634979 is 97943602.

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 20634979 - 2⁷ = 20634851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20634949) 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, 14802 + ... + 16135.

It is an arithmetic number, because the mean of its divisors is an integer number (2784420).

Almost surely, 2^20634979 is an apocalyptic number.

20634979 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20634979 is a deficient number, since it is larger than the sum of its proper divisors (1640381).

20634979 is a wasteful number, since it uses less digits than its factorization.

20634979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30989.

The product of its (nonzero) digits is 81648, while the sum is 40.

The square root of 20634979 is about 4542.5740500293. The cubic root of 20634979 is about 274.2845490841.

The spelling of 20634979 in words is "twenty million, six hundred thirty-four thousand, nine hundred seventy-nine".