20990949 has 16 divisors (see below), whose sum is σ = 32374272. Its totient is φ = 11849328.

The previous prime is 20990947. The next prime is 20990969. The reversal of 20990949 is 94909902.

It is not a de Polignac number, because 20990949 - 2¹ = 20990947 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20990949.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20990947) 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 15 ways as a sum of consecutive naturals, for example, 4279 + ... + 7764.

It is an arithmetic number, because the mean of its divisors is an integer number (2023392).

Almost surely, 2^20990949 is an apocalyptic number.

It is an amenable number.

20990949 is a deficient number, since it is larger than the sum of its proper divisors (11383323).

20990949 is a wasteful number, since it uses less digits than its factorization.

20990949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12136.

The product of its (nonzero) digits is 52488, while the sum is 42.

The square root of 20990949 is about 4581.5880434627. The cubic root of 20990949 is about 275.8527753983.

The spelling of 20990949 in words is "twenty million, nine hundred ninety thousand, nine hundred forty-nine".