20918799 has 24 divisors (see below), whose sum is σ = 34399872. Its totient is φ = 12125520.

The previous prime is 20918783. The next prime is 20918813. The reversal of 20918799 is 99781902.

It is not a de Polignac number, because 20918799 - 2⁴ = 20918783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20918749) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2317 + ... + 6870.

It is an arithmetic number, because the mean of its divisors is an integer number (1433328).

Almost surely, 2^20918799 is an apocalyptic number.

20918799 is a deficient number, since it is larger than the sum of its proper divisors (13481073).

20918799 is a wasteful number, since it uses less digits than its factorization.

20918799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9227 (or 9224 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 20918799 is about 4573.7073583691. The cubic root of 20918799 is about 275.5363592668.

It can be divided in two parts, 20 and 918799, that added together give a palindrome (918819).

The spelling of 20918799 in words is "twenty million, nine hundred eighteen thousand, seven hundred ninety-nine".