21813932 has 12 divisors (see below), whose sum is σ = 43627920. Its totient is φ = 9348816.

The previous prime is 21813931. The next prime is 21813937. The reversal of 21813932 is 23931812.

21813932 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21813895 and 21813904.

It is not an unprimeable number, because it can be changed into a prime (21813931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 389507 + ... + 389562.

It is an arithmetic number, because the mean of its divisors is an integer number (3635660).

Almost surely, 2^21813932 is an apocalyptic number.

It is an amenable number.

21813932 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21813932 is a wasteful number, since it uses less digits than its factorization.

21813932 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779080 (or 779078 counting only the distinct ones).

The product of its digits is 2592, while the sum is 29.

The square root of 21813932 is about 4670.5387269565. The cubic root of 21813932 is about 279.4117411686.

The spelling of 21813932 in words is "twenty-one million, eight hundred thirteen thousand, nine hundred thirty-two".