125637991 has 2 divisors, whose sum is σ = 125637992. Its totient is φ = 125637990.

The previous prime is 125637929. The next prime is 125638021. The reversal of 125637991 is 199736521.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 125637991 - 2¹³ = 125629799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (125617991) 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 as a sum of consecutive naturals, namely, 62818995 + 62818996.

It is an arithmetic number, because the mean of its divisors is an integer number (62818996).

Almost surely, 2^125637991 is an apocalyptic number.

125637991 is a deficient number, since it is larger than the sum of its proper divisors (1).

125637991 is an equidigital number, since it uses as much as digits as its factorization.

125637991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 102060, while the sum is 43.

The square root of 125637991 is about 11208.8353989163. The cubic root of 125637991 is about 500.8492115297.

The spelling of 125637991 in words is "one hundred twenty-five million, six hundred thirty-seven thousand, nine hundred ninety-one".