21437204 has 24 divisors (see below), whose sum is σ = 39876480. Its totient is φ = 10048896.

The previous prime is 21437201. The next prime is 21437231. The reversal of 21437204 is 40273412.

It is a self number, because there is not a number n which added to its sum of digits gives 21437204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21437201) 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, 24527 + ... + 25385.

It is an arithmetic number, because the mean of its divisors is an integer number (1661520).

Almost surely, 2^21437204 is an apocalyptic number.

It is an amenable number.

21437204 is a deficient number, since it is larger than the sum of its proper divisors (18439276).

21437204 is a wasteful number, since it uses less digits than its factorization.

21437204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1247 (or 1245 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21437204 is about 4630.0328292573. The cubic root of 21437204 is about 277.7939055288.

The spelling of 21437204 in words is "twenty-one million, four hundred thirty-seven thousand, two hundred four".