123720831 has 16 divisors (see below), whose sum is σ = 197389920. Its totient is φ = 76135680.

The previous prime is 123720827. The next prime is 123720833. The reversal of 123720831 is 138027321.

It is not a de Polignac number, because 123720831 - 2² = 123720827 is a prime.

It is a super-2 number, since 2×123720831² = 30613688046661122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 123720795 and 123720804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123720833) 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, 175890 + ... + 176591.

It is an arithmetic number, because the mean of its divisors is an integer number (12336870).

Almost surely, 2^123720831 is an apocalyptic number.

123720831 is a deficient number, since it is larger than the sum of its proper divisors (73669089).

123720831 is a wasteful number, since it uses less digits than its factorization.

123720831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352503 (or 352497 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 123720831 is about 11122.9866043253. The cubic root of 123720831 is about 498.2885901696.

The spelling of 123720831 in words is "one hundred twenty-three million, seven hundred twenty thousand, eight hundred thirty-one".