123145681 has 2 divisors, whose sum is σ = 123145682. Its totient is φ = 123145680.

The previous prime is 123145661. The next prime is 123145691. The reversal of 123145681 is 186541321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123099025 + 46656 = 11095^2 + 216^2 .

It is a cyclic number.

It is not a de Polignac number, because 123145681 - 2¹⁹ = 122621393 is a prime.

It is a super-2 number, since 2×123145681² = 30329717497907522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (123145621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61572840 + 61572841.

It is an arithmetic number, because the mean of its divisors is an integer number (61572841).

Almost surely, 2^123145681 is an apocalyptic number.

It is an amenable number.

123145681 is a deficient number, since it is larger than the sum of its proper divisors (1).

123145681 is an equidigital number, since it uses as much as digits as its factorization.

123145681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 31.

The square root of 123145681 is about 11097.1023695377. The cubic root of 123145681 is about 497.5152471275.

The spelling of 123145681 in words is "one hundred twenty-three million, one hundred forty-five thousand, six hundred eighty-one".