20979123 has 8 divisors (see below), whose sum is σ = 30515136. Its totient is φ = 12714600.

The previous prime is 20979109. The next prime is 20979137. The reversal of 20979123 is 32197902.

It is an interprime number because it is at equal distance from previous prime (20979109) and next prime (20979137).

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

It is not a de Polignac number, because 20979123 - 2⁹ = 20978611 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 635731 = 20979123 / (2 + 0 + 9 + 7 + 9 + 1 + 2 + 3).

It is not an unprimeable number, because it can be changed into a prime (20979223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 317833 + ... + 317898.

It is an arithmetic number, because the mean of its divisors is an integer number (3814392).

Almost surely, 2^20979123 is an apocalyptic number.

20979123 is a deficient number, since it is larger than the sum of its proper divisors (9536013).

20979123 is a wasteful number, since it uses less digits than its factorization.

20979123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 635745.

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 20979123 is about 4580.2972610956. The cubic root of 20979123 is about 275.8009618326.

The spelling of 20979123 in words is "twenty million, nine hundred seventy-nine thousand, one hundred twenty-three".