125521831 has 4 divisors (see below), whose sum is σ = 129850200. Its totient is φ = 121193464.

The previous prime is 125521817. The next prime is 125521841. The reversal of 125521831 is 138125521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 138125521 = 29 ⋅4762949.

It is a cyclic number.

It is not a de Polignac number, because 125521831 - 2¹¹ = 125519783 is a prime.

It is a super-2 number, since 2×125521831² = 31511460115185122, which 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 125521831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125521801) 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, 2164141 + ... + 2164198.

It is an arithmetic number, because the mean of its divisors is an integer number (32462550).

Almost surely, 2^125521831 is an apocalyptic number.

125521831 is a deficient number, since it is larger than the sum of its proper divisors (4328369).

125521831 is an equidigital number, since it uses as much as digits as its factorization.

125521831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4328368.

The product of its digits is 2400, while the sum is 28.

The square root of 125521831 is about 11203.6525740492. The cubic root of 125521831 is about 500.6948087012.

The spelling of 125521831 in words is "one hundred twenty-five million, five hundred twenty-one thousand, eight hundred thirty-one".