20990518 has 8 divisors (see below), whose sum is σ = 31651200. Its totient is φ = 10440120.

The previous prime is 20990479. The next prime is 20990521. The reversal of 20990518 is 81509902.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27093 + ... + 27856.

It is an arithmetic number, because the mean of its divisors is an integer number (3956400).

Almost surely, 2^20990518 is an apocalyptic number.

20990518 is a deficient number, since it is larger than the sum of its proper divisors (10660682).

20990518 is a wasteful number, since it uses less digits than its factorization.

20990518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55142.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 20990518 is about 4581.5410071285. The cubic root of 20990518 is about 275.8508873884.

The spelling of 20990518 in words is "twenty million, nine hundred ninety thousand, five hundred eighteen".