123117120721 has 16 divisors (see below), whose sum is σ = 149469654400. Its totient is φ = 99057593088.

The previous prime is 123117120691. The next prime is 123117120727. The reversal of 123117120721 is 127021711321.

It is a cyclic number.

It is not a de Polignac number, because 123117120721 - 2²⁵ = 123083566289 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 123117120721.

It is not an unprimeable number, because it can be changed into a prime (123117120727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4231800 + ... + 4260793.

It is an arithmetic number, because the mean of its divisors is an integer number (9341853400).

Almost surely, 2^123117120721 is an apocalyptic number.

It is an amenable number.

123117120721 is a deficient number, since it is larger than the sum of its proper divisors (26352533679).

123117120721 is a wasteful number, since it uses less digits than its factorization.

123117120721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8492728.

The product of its (nonzero) digits is 1176, while the sum is 28.

The spelling of 123117120721 in words is "one hundred twenty-three billion, one hundred seventeen million, one hundred twenty thousand, seven hundred twenty-one".