123819931 has 2 divisors, whose sum is σ = 123819932. Its totient is φ = 123819930.

The previous prime is 123819929. The next prime is 123819973. The reversal of 123819931 is 139918321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 123819931 - 2¹ = 123819929 is a prime.

It is a super-2 number, since 2×123819931² = 30662750625689522, which contains 22 as substring.

Together with 123819929, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (123819911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61909965 + 61909966.

It is an arithmetic number, because the mean of its divisors is an integer number (61909966).

Almost surely, 2^123819931 is an apocalyptic number.

123819931 is a deficient number, since it is larger than the sum of its proper divisors (1).

123819931 is an equidigital number, since it uses as much as digits as its factorization.

123819931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11664, while the sum is 37.

The square root of 123819931 is about 11127.4404514246. The cubic root of 123819931 is about 498.4215971990.

It can be divided in two parts, 123819 and 931, that added together give a triangular number (124750 = T₄₉₉).

The spelling of 123819931 in words is "one hundred twenty-three million, eight hundred nineteen thousand, nine hundred thirty-one".