20979451 has 8 divisors (see below), whose sum is σ = 21294224. Its totient is φ = 20666880.

The previous prime is 20979443. The next prime is 20979461. The reversal of 20979451 is 15497902.

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 20979451 - 2³ = 20979443 is a prime.

It is a super-2 number, since 2×20979451² = 880274728522802, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20979451.

It is not an unprimeable number, because it can be changed into a prime (20979421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30016 + ... + 30706.

It is an arithmetic number, because the mean of its divisors is an integer number (2661778).

Almost surely, 2^20979451 is an apocalyptic number.

20979451 is a deficient number, since it is larger than the sum of its proper divisors (314773).

20979451 is an equidigital number, since it uses as much as digits as its factorization.

20979451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 20979451 is about 4580.3330664920. Note that the first 3 decimals coincide. The cubic root of 20979451 is about 275.8023991701.

The spelling of 20979451 in words is "twenty million, nine hundred seventy-nine thousand, four hundred fifty-one".