123731681 has 2 divisors, whose sum is σ = 123731682. Its totient is φ = 123731680.

The previous prime is 123731659. The next prime is 123731689. The reversal of 123731681 is 186137321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118048225 + 5683456 = 10865^2 + 2384^2 .

It is a cyclic number.

It is not a de Polignac number, because 123731681 - 2¹⁰ = 123730657 is a prime.

It is a super-2 number, since 2×123731681² = 30619057766171522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (123731689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61865840 + 61865841.

It is an arithmetic number, because the mean of its divisors is an integer number (61865841).

Almost surely, 2^123731681 is an apocalyptic number.

It is an amenable number.

123731681 is a deficient number, since it is larger than the sum of its proper divisors (1).

123731681 is an equidigital number, since it uses as much as digits as its factorization.

123731681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 32.

The square root of 123731681 is about 11123.4743223509. The cubic root of 123731681 is about 498.3031559548.

The spelling of 123731681 in words is "one hundred twenty-three million, seven hundred thirty-one thousand, six hundred eighty-one".