123456691 has 2 divisors, whose sum is σ = 123456692. Its totient is φ = 123456690.

The previous prime is 123456677. The next prime is 123456719. The reversal of 123456691 is 196654321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 123456691 - 2⁷ = 123456563 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123456691.

It is not a weakly prime, because it can be changed into another prime (123456611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61728345 + 61728346.

It is an arithmetic number, because the mean of its divisors is an integer number (61728346).

Almost surely, 2^123456691 is an apocalyptic number.

123456691 is a deficient number, since it is larger than the sum of its proper divisors (1).

123456691 is an equidigital number, since it uses as much as digits as its factorization.

123456691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 37.

The square root of 123456691 is about 11111.1066505547. The cubic root of 123456691 is about 497.9337274648.

The spelling of 123456691 in words is "one hundred twenty-three million, four hundred fifty-six thousand, six hundred ninety-one".