21123310104 has 48 divisors (see below), whose sum is σ = 61609657200. Its totient is φ = 6499479744.

The previous prime is 21123310073. The next prime is 21123310111. The reversal of 21123310104 is 40101332112.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11282884 + ... + 11284755.

It is an arithmetic number, because the mean of its divisors is an integer number (1283534525).

Almost surely, 2^21123310104 is an apocalyptic number.

21123310104 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21123310104 is an abundant number, since it is smaller than the sum of its proper divisors (40486347096).

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

21123310104 is a wasteful number, since it uses less digits than its factorization.

21123310104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22567664 (or 22567657 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21123310104 its reverse (40101332112), we get a palindrome (61224642216).

The spelling of 21123310104 in words is "twenty-one billion, one hundred twenty-three million, three hundred ten thousand, one hundred four".