21155041204 has 24 divisors (see below), whose sum is σ = 41689702656. Its totient is φ = 9305736000.

The previous prime is 21155041181. The next prime is 21155041253. The reversal of 21155041204 is 40214055112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7753417 + ... + 7756144.

It is an arithmetic number, because the mean of its divisors is an integer number (1737070944).

Almost surely, 2^21155041204 is an apocalyptic number.

It is an amenable number.

21155041204 is a deficient number, since it is larger than the sum of its proper divisors (20534661452).

21155041204 is a wasteful number, since it uses less digits than its factorization.

21155041204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15509607 (or 15509605 counting only the distinct ones).

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

Adding to 21155041204 its reverse (40214055112), we get a palindrome (61369096316).

The spelling of 21155041204 in words is "twenty-one billion, one hundred fifty-five million, forty-one thousand, two hundred four".