125661431 has 6 divisors (see below), whose sum is σ = 146177640. Its totient is φ = 107709756.

The previous prime is 125661377. The next prime is 125661449. The reversal of 125661431 is 134166521.

It is a happy number.

It is not a de Polignac number, because 125661431 - 2²² = 121467127 is a prime.

It is a super-2 number, since 2×125661431² = 31581590481935522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 125661394 and 125661403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125661451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1282211 + ... + 1282308.

It is an arithmetic number, because the mean of its divisors is an integer number (24362940).

Almost surely, 2^125661431 is an apocalyptic number.

125661431 is a deficient number, since it is larger than the sum of its proper divisors (20516209).

125661431 is an equidigital number, since it uses as much as digits as its factorization.

125661431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2564533 (or 2564526 counting only the distinct ones).

The product of its digits is 4320, while the sum is 29.

The square root of 125661431 is about 11209.8809538728. The cubic root of 125661431 is about 500.8803570333.

The spelling of 125661431 in words is "one hundred twenty-five million, six hundred sixty-one thousand, four hundred thirty-one".