123311920 has 80 divisors (see below), whose sum is σ = 295695360. Its totient is φ = 47803392.

The previous prime is 123311899. The next prime is 123311921. The reversal of 123311920 is 29113321.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×123311920² = 30411659228172800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 123311891 and 123311900.

It is not an unprimeable number, because it can be changed into a prime (123311921) 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, 538366 + ... + 538594.

It is an arithmetic number, because the mean of its divisors is an integer number (3696192).

Almost surely, 2^123311920 is an apocalyptic number.

123311920 is a gapful number since it is divisible by the number (10) 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 123311920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147847680).

123311920 is an abundant number, since it is smaller than the sum of its proper divisors (172383440).

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

123311920 is a wasteful number, since it uses less digits than its factorization.

123311920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422 (or 416 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 123311920 is about 11104.5900419601. The cubic root of 123311920 is about 497.7390179984.

The spelling of 123311920 in words is "one hundred twenty-three million, three hundred eleven thousand, nine hundred twenty".