125851561 has 32 divisors (see below), whose sum is σ = 157075200. Its totient is φ = 99348480.

The previous prime is 125851559. The next prime is 125851613. The reversal of 125851561 is 165158521.

It is not a de Polignac number, because 125851561 - 2¹ = 125851559 is a prime.

It is a super-2 number, since 2×125851561² = 31677230812273442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125851501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 124225 + ... + 125233.

It is an arithmetic number, because the mean of its divisors is an integer number (4908600).

Almost surely, 2^125851561 is an apocalyptic number.

125851561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

125851561 is a deficient number, since it is larger than the sum of its proper divisors (31223639).

125851561 is a wasteful number, since it uses less digits than its factorization.

125851561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1089.

The product of its digits is 12000, while the sum is 34.

The square root of 125851561 is about 11218.3582132146. The cubic root of 125851561 is about 501.1328460479.

The spelling of 125851561 in words is "one hundred twenty-five million, eight hundred fifty-one thousand, five hundred sixty-one".