21123010104 has 128 divisors (see below), whose sum is σ = 61047767040. Its totient is φ = 5965736832.

The previous prime is 21123010081. The next prime is 21123010159. The reversal of 21123010104 is 40101032112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18808887 + ... + 18810009.

It is an arithmetic number, because the mean of its divisors is an integer number (476935680).

Almost surely, 2^21123010104 is an apocalyptic number.

21123010104 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123010104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30523883520).

21123010104 is an abundant number, since it is smaller than the sum of its proper divisors (39924756936).

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

21123010104 is a wasteful number, since it uses less digits than its factorization.

21123010104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2329 (or 2325 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21123010104 its reverse (40101032112), we get a palindrome (61224042216).

The spelling of 21123010104 in words is "twenty-one billion, one hundred twenty-three million, ten thousand, one hundred four".