21400203204 has 36 divisors (see below), whose sum is σ = 54351351600. Its totient is φ = 7099590960.

The previous prime is 21400203203. The next prime is 21400203217. The reversal of 21400203204 is 40230200412.

It is a tau number, because it is divible by the number of its divisors (36).

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 (21400203203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1401054 + ... + 1416245.

Almost surely, 2^21400203204 is an apocalyptic number.

It is an amenable number.

21400203204 is an abundant number, since it is smaller than the sum of its proper divisors (32951148396).

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

21400203204 is a wasteful number, since it uses less digits than its factorization.

21400203204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2817520 (or 2817515 counting only the distinct ones).

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

Adding to 21400203204 its reverse (40230200412), we get a palindrome (61630403616).

The spelling of 21400203204 in words is "twenty-one billion, four hundred million, two hundred three thousand, two hundred four".