21911802 has 16 divisors (see below), whose sum is σ = 47807712. Its totient is φ = 6639920.

The previous prime is 21911797. The next prime is 21911803. The reversal of 21911802 is 20811912.

It is not an unprimeable number, because it can be changed into a prime (21911803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165933 + ... + 166064.

It is an arithmetic number, because the mean of its divisors is an integer number (2987982).

Almost surely, 2^21911802 is an apocalyptic number.

21911802 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21911802 is an abundant number, since it is smaller than the sum of its proper divisors (25895910).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21911802 is a wasteful number, since it uses less digits than its factorization.

21911802 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332013.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 21911802 is about 4681.0043794041. The cubic root of 21911802 is about 279.8289857077.

It can be divided in two parts, 2191 and 1802, that added together give a palindrome (3993).

The spelling of 21911802 in words is "twenty-one million, nine hundred eleven thousand, eight hundred two".