21331746 has 24 divisors (see below), whose sum is σ = 46303920. Its totient is φ = 7097496.

The previous prime is 21331729. The next prime is 21331777. The reversal of 21331746 is 64713312.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 17761 + ... + 18923.

It is an arithmetic number, because the mean of its divisors is an integer number (1929330).

Almost surely, 2^21331746 is an apocalyptic number.

21331746 is an abundant number, since it is smaller than the sum of its proper divisors (24972174).

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

21331746 is a wasteful number, since it uses less digits than its factorization.

21331746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2190 (or 2187 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 21331746 is about 4618.6303164466. The cubic root of 21331746 is about 277.3376308480.

The spelling of 21331746 in words is "twenty-one million, three hundred thirty-one thousand, seven hundred forty-six".