21403004 has 18 divisors (see below), whose sum is σ = 43570800. Its totient is φ = 9172632.

The previous prime is 21402977. The next prime is 21403013. The reversal of 21403004 is 40030412.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a self number, because there is not a number n which added to its sum of digits gives 21403004.

It is a congruent number.

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 5 ways as a sum of consecutive naturals, for example, 54404 + ... + 54795.

It is an arithmetic number, because the mean of its divisors is an integer number (2420600).

Almost surely, 2^21403004 is an apocalyptic number.

It is an amenable number.

21403004 is an abundant number, since it is smaller than the sum of its proper divisors (22167796).

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

21403004 is a wasteful number, since it uses less digits than its factorization.

21403004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109217 (or 109208 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21403004 is about 4626.3380767082. The cubic root of 21403004 is about 277.6461000546.

Adding to 21403004 its reverse (40030412), we get a palindrome (61433416).

The spelling of 21403004 in words is "twenty-one million, four hundred three thousand, four".