123991601 has 2 divisors, whose sum is σ = 123991602. Its totient is φ = 123991600.

The previous prime is 123991579. The next prime is 123991633. The reversal of 123991601 is 106199321.

It is an a-pointer prime, because the next prime (123991633) can be obtained adding 123991601 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 112869376 + 11122225 = 10624^2 + 3335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123991601 is a prime.

It is not a weakly prime, because it can be changed into another prime (123991201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61995800 + 61995801.

It is an arithmetic number, because the mean of its divisors is an integer number (61995801).

Almost surely, 2^123991601 is an apocalyptic number.

It is an amenable number.

123991601 is a deficient number, since it is larger than the sum of its proper divisors (1).

123991601 is an equidigital number, since it uses as much as digits as its factorization.

123991601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 123991601 is about 11135.1515930408. The cubic root of 123991601 is about 498.6518361757.

The spelling of 123991601 in words is "one hundred twenty-three million, nine hundred ninety-one thousand, six hundred one".