21103121504 has 24 divisors (see below), whose sum is σ = 41558355720. Its totient is φ = 10548618496.

The previous prime is 21103121467. The next prime is 21103121519. The reversal of 21103121504 is 40512130112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26972 + ... + 207204.

It is an arithmetic number, because the mean of its divisors is an integer number (1731598155).

Almost surely, 2^21103121504 is an apocalyptic number.

It is an amenable number.

21103121504 is a deficient number, since it is larger than the sum of its proper divisors (20455234216).

21103121504 is a wasteful number, since it uses less digits than its factorization.

21103121504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183902 (or 183894 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 21103121504 its reverse (40512130112), we get a palindrome (61615251616).

The spelling of 21103121504 in words is "twenty-one billion, one hundred three million, one hundred twenty-one thousand, five hundred four".