125131621 has 4 divisors (see below), whose sum is σ = 125447212. Its totient is φ = 124816032.

The previous prime is 125131613. The next prime is 125131639. The reversal of 125131621 is 126131521.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43428100 + 81703521 = 6590^2 + 9039^2 .

It is a cyclic number.

It is not a de Polignac number, because 125131621 - 2³ = 125131613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 125131592 and 125131601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125131681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157200 + ... + 157993.

It is an arithmetic number, because the mean of its divisors is an integer number (31361803).

Almost surely, 2^125131621 is an apocalyptic number.

It is an amenable number.

125131621 is a deficient number, since it is larger than the sum of its proper divisors (315591).

125131621 is an equidigital number, since it uses as much as digits as its factorization.

125131621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315590.

The product of its digits is 360, while the sum is 22.

The square root of 125131621 is about 11186.2246088660. The cubic root of 125131621 is about 500.1754331059.

The spelling of 125131621 in words is "one hundred twenty-five million, one hundred thirty-one thousand, six hundred twenty-one".