21123120102 has 16 divisors (see below), whose sum is σ = 48281417472. Its totient is φ = 6035177160.

The previous prime is 21123120023. The next prime is 21123120113. The reversal of 21123120102 is 20102132112.

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, 251465674 + ... + 251465757.

It is an arithmetic number, because the mean of its divisors is an integer number (3017588592).

Almost surely, 2^21123120102 is an apocalyptic number.

21123120102 is an abundant number, since it is smaller than the sum of its proper divisors (27158297370).

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

21123120102 is a wasteful number, since it uses less digits than its factorization.

21123120102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502931443.

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

Adding to 21123120102 its reverse (20102132112), we get a palindrome (41225252214).

The spelling of 21123120102 in words is "twenty-one billion, one hundred twenty-three million, one hundred twenty thousand, one hundred two".