20904279 has 8 divisors (see below), whose sum is σ = 30406272. Its totient is φ = 12669240.

The previous prime is 20904277. The next prime is 20904281. The reversal of 20904279 is 97240902.

It is an interprime number because it is at equal distance from previous prime (20904277) and next prime (20904281).

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

It is not a de Polignac number, because 20904279 - 2¹ = 20904277 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: 633463 = 20904279 / (2 + 0 + 9 + 0 + 4 + 2 + 7 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20904277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 316699 + ... + 316764.

It is an arithmetic number, because the mean of its divisors is an integer number (3800784).

Almost surely, 2^20904279 is an apocalyptic number.

20904279 is a deficient number, since it is larger than the sum of its proper divisors (9501993).

20904279 is a wasteful number, since it uses less digits than its factorization.

20904279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633477.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 20904279 is about 4572.1197490879. The cubic root of 20904279 is about 275.4725934334.

The spelling of 20904279 in words is "twenty million, nine hundred four thousand, two hundred seventy-nine".