123516661 has 2 divisors, whose sum is σ = 123516662. Its totient is φ = 123516660.

The previous prime is 123516649. The next prime is 123516691. The reversal of 123516661 is 166615321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 110376036 + 13140625 = 10506^2 + 3625^2 .

It is a cyclic number.

It is not a de Polignac number, because 123516661 - 2⁵ = 123516629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123516691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61758330 + 61758331.

It is an arithmetic number, because the mean of its divisors is an integer number (61758331).

Almost surely, 2^123516661 is an apocalyptic number.

It is an amenable number.

123516661 is a deficient number, since it is larger than the sum of its proper divisors (1).

123516661 is an equidigital number, since it uses as much as digits as its factorization.

123516661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 31.

The square root of 123516661 is about 11113.8049739952. The cubic root of 123516661 is about 498.0143394096.

The spelling of 123516661 in words is "one hundred twenty-three million, five hundred sixteen thousand, six hundred sixty-one".