21155104204 has 48 divisors (see below), whose sum is σ = 40475848672. Its totient is φ = 9615739392.

The previous prime is 21155104199. The next prime is 21155104213. The reversal of 21155104204 is 40240155112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2778667 + ... + 2786269.

Almost surely, 2^21155104204 is an apocalyptic number.

It is an amenable number.

21155104204 is a deficient number, since it is larger than the sum of its proper divisors (19320744468).

21155104204 is a wasteful number, since it uses less digits than its factorization.

21155104204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8426 (or 8424 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

Adding to 21155104204 its reverse (40240155112), we get a palindrome (61395259316).

The spelling of 21155104204 in words is "twenty-one billion, one hundred fifty-five million, one hundred four thousand, two hundred four".