125513561 has 8 divisors (see below), whose sum is σ = 126436800. Its totient is φ = 124593840.

The previous prime is 125513551. The next prime is 125513581. The reversal of 125513561 is 165315521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 125513561 - 2¹⁸ = 125251417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125513501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149180 + ... + 150018.

It is an arithmetic number, because the mean of its divisors is an integer number (15804600).

Almost surely, 2^125513561 is an apocalyptic number.

It is an amenable number.

125513561 is a deficient number, since it is larger than the sum of its proper divisors (923239).

125513561 is an equidigital number, since it uses as much as digits as its factorization.

125513561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1759.

The product of its digits is 4500, while the sum is 29.

The square root of 125513561 is about 11203.2834919054. The cubic root of 125513561 is about 500.6838123749.

The spelling of 125513561 in words is "one hundred twenty-five million, five hundred thirteen thousand, five hundred sixty-one".