21403332 has 24 divisors (see below), whose sum is σ = 55490400. Its totient is φ = 7134408.

The previous prime is 21403313. The next prime is 21403337. The reversal of 21403332 is 23330412.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21403337) 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 7 ways as a sum of consecutive naturals, for example, 98982 + ... + 99197.

It is an arithmetic number, because the mean of its divisors is an integer number (2312100).

Almost surely, 2^21403332 is an apocalyptic number.

It is an amenable number.

21403332 is an abundant number, since it is smaller than the sum of its proper divisors (34087068).

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

21403332 is a wasteful number, since it uses less digits than its factorization.

21403332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198192 (or 198184 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 21403332 is about 4626.3735257759. The cubic root of 21403332 is about 277.6475183517.

Adding to 21403332 its reverse (23330412), we get a palindrome (44733744).

The spelling of 21403332 in words is "twenty-one million, four hundred three thousand, three hundred thirty-two".