123455681 has 2 divisors, whose sum is σ = 123455682. Its totient is φ = 123455680.

The previous prime is 123455677. The next prime is 123455687. The reversal of 123455681 is 186554321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122855056 + 600625 = 11084^2 + 775^2 .

It is a cyclic number.

It is not a de Polignac number, because 123455681 - 2² = 123455677 is a prime.

It is a super-2 number, since 2×123455681² = 30482610342347522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (123455687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61727840 + 61727841.

It is an arithmetic number, because the mean of its divisors is an integer number (61727841).

Almost surely, 2^123455681 is an apocalyptic number.

It is an amenable number.

123455681 is a deficient number, since it is larger than the sum of its proper divisors (1).

123455681 is an equidigital number, since it uses as much as digits as its factorization.

123455681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28800, while the sum is 35.

The square root of 123455681 is about 11111.0612004435. The cubic root of 123455681 is about 497.9323695948.

The spelling of 123455681 in words is "one hundred twenty-three million, four hundred fifty-five thousand, six hundred eighty-one".