125517861225 has 45 divisors (see below), whose sum is σ = 232532003253. Its totient is φ = 66934356480.

The previous prime is 125517861187. The next prime is 125517861239. The reversal of 125517861225 is 522168715521.

It is a happy number.

The square root of 125517861225 is 354285.

It is a perfect power (a square), and thus also a powerful number.

125517861225 is a `hidden beast` number, since 1 + 2 + 5 + 5 + 1 + 7 + 8 + 612 + 25 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 58538350809 + 66979510416 = 241947^2 + 258804^2 .

It is a tau number, because it is divible by the number of its divisors (45).

It is not a de Polignac number, because 125517861225 - 2²⁹ = 124980990313 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 44 ways as a sum of consecutive naturals, for example, 15938889 + ... + 15946761.

Almost surely, 2^125517861225 is an apocalyptic number.

125517861225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

125517861225 is the 354285-th square number.

125517861225 is the 177143-rd centered octagonal number.

It is an amenable number.

125517861225 is a deficient number, since it is larger than the sum of its proper divisors (107014142028).

125517861225 is an frugal number, since it uses more digits than its factorization.

125517861225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15768 (or 7881 counting only the distinct ones).

The product of its digits is 336000, while the sum is 45.

The spelling of 125517861225 in words is "one hundred twenty-five billion, five hundred seventeen million, eight hundred sixty-one thousand, two hundred twenty-five".