123391813 has 2 divisors, whose sum is σ = 123391814. Its totient is φ = 123391812.

The previous prime is 123391789. The next prime is 123391843. The reversal of 123391813 is 318193321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119639844 + 3751969 = 10938^2 + 1937^2 .

It is a cyclic number.

It is not a de Polignac number, because 123391813 - 2¹³ = 123383621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123391843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61695906 + 61695907.

It is an arithmetic number, because the mean of its divisors is an integer number (61695907).

Almost surely, 2^123391813 is an apocalyptic number.

It is an amenable number.

123391813 is a deficient number, since it is larger than the sum of its proper divisors (1).

123391813 is an equidigital number, since it uses as much as digits as its factorization.

123391813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 31.

The square root of 123391813 is about 11108.1867557221. The cubic root of 123391813 is about 497.8464887616.

The spelling of 123391813 in words is "one hundred twenty-three million, three hundred ninety-one thousand, eight hundred thirteen".