125643557 has 12 divisors (see below), whose sum is σ = 139377924. Its totient is φ = 113143680.

The previous prime is 125643547. The next prime is 125643569. The reversal of 125643557 is 755346521.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 54257956 + 71385601 = 7366^2 + 8449^2 .

It is not a de Polignac number, because 125643557 - 2¹⁰ = 125642533 is a prime.

It is a super-2 number, since 2×125643557² = 31572606831224498, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 125643557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125643547) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2138 + ... + 15995.

It is an arithmetic number, because the mean of its divisors is an integer number (11614827).

Almost surely, 2^125643557 is an apocalyptic number.

It is an amenable number.

125643557 is a deficient number, since it is larger than the sum of its proper divisors (13734367).

125643557 is a wasteful number, since it uses less digits than its factorization.

125643557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18200 (or 18187 counting only the distinct ones).

The product of its digits is 126000, while the sum is 38.

The square root of 125643557 is about 11209.0836824426. The cubic root of 125643557 is about 500.8566076087.

The spelling of 125643557 in words is "one hundred twenty-five million, six hundred forty-three thousand, five hundred fifty-seven".