125981632169 has 4 divisors (see below), whose sum is σ = 125995221444. Its totient is φ = 125968042896.

The previous prime is 125981632099. The next prime is 125981632207. The reversal of 125981632169 is 961236189521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 961236189521 = 389 ⋅2471044189.

It can be written as a sum of positive squares in 2 ways, for example, as 47682399769 + 78299232400 = 218363^2 + 279820^2 .

It is a cyclic number.

It is not a de Polignac number, because 125981632169 - 2²⁰ = 125980583593 is a prime.

It is a super-2 number, since 2×125981632169² (a number of 23 digits) 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 125981632169.

It is not an unprimeable number, because it can be changed into a prime (125981632069) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6780722 + ... + 6799275.

It is an arithmetic number, because the mean of its divisors is an integer number (31498805361).

Almost surely, 2^125981632169 is an apocalyptic number.

It is an amenable number.

125981632169 is a deficient number, since it is larger than the sum of its proper divisors (13589275).

125981632169 is an equidigital number, since it uses as much as digits as its factorization.

125981632169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13589274.

The product of its digits is 1399680, while the sum is 53.

The spelling of 125981632169 in words is "one hundred twenty-five billion, nine hundred eighty-one million, six hundred thirty-two thousand, one hundred sixty-nine".