123400391 has 2 divisors, whose sum is σ = 123400392. Its totient is φ = 123400390.

The previous prime is 123400379. The next prime is 123400397. The reversal of 123400391 is 193004321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 123400391 - 2¹⁴ = 123384007 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123400397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61700195 + 61700196.

It is an arithmetic number, because the mean of its divisors is an integer number (61700196).

Almost surely, 2^123400391 is an apocalyptic number.

123400391 is a deficient number, since it is larger than the sum of its proper divisors (1).

123400391 is an equidigital number, since it uses as much as digits as its factorization.

123400391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 123400391 is about 11108.5728606334. The cubic root of 123400391 is about 497.8580249894.

The spelling of 123400391 in words is "one hundred twenty-three million, four hundred thousand, three hundred ninety-one".