21324402 has 24 divisors (see below), whose sum is σ = 50403600. Its totient is φ = 6461880.

The previous prime is 21324389. The next prime is 21324419. The reversal of 21324402 is 20442312.

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

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 53652 + ... + 54047.

It is an arithmetic number, because the mean of its divisors is an integer number (2100150).

Almost surely, 2^21324402 is an apocalyptic number.

21324402 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21324402 is an abundant number, since it is smaller than the sum of its proper divisors (29079198).

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

21324402 is a wasteful number, since it uses less digits than its factorization.

21324402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107718 (or 107715 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 21324402 is about 4617.8352071073. The cubic root of 21324402 is about 277.3058003336.

Adding to 21324402 its reverse (20442312), we get a palindrome (41766714).

It can be divided in two parts, 21 and 324402, that added together give a palindrome (324423).

The spelling of 21324402 in words is "twenty-one million, three hundred twenty-four thousand, four hundred two".