125506561 has 4 divisors (see below), whose sum is σ = 130963392. Its totient is φ = 120049732.

The previous prime is 125506559. The next prime is 125506573. The reversal of 125506561 is 165605521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165605521 = 10939 ⋅15139.

It is a cyclic number.

It is not a de Polignac number, because 125506561 - 2¹ = 125506559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125506261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2728381 + ... + 2728426.

It is an arithmetic number, because the mean of its divisors is an integer number (32740848).

Almost surely, 2^125506561 is an apocalyptic number.

It is an amenable number.

125506561 is a deficient number, since it is larger than the sum of its proper divisors (5456831).

125506561 is an equidigital number, since it uses as much as digits as its factorization.

125506561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5456830.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 125506561 is about 11202.9710791379. The cubic root of 125506561 is about 500.6745043453.

The spelling of 125506561 in words is "one hundred twenty-five million, five hundred six thousand, five hundred sixty-one".