125663991 has 8 divisors (see below), whose sum is σ = 167662320. Its totient is φ = 83720832.

The previous prime is 125663981. The next prime is 125664013. The reversal of 125663991 is 199366521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 125663991 - 2⁵ = 125663959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125663911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8146 + ... + 17823.

It is an arithmetic number, because the mean of its divisors is an integer number (20957790).

Almost surely, 2^125663991 is an apocalyptic number.

125663991 is a deficient number, since it is larger than the sum of its proper divisors (41998329).

125663991 is a wasteful number, since it uses less digits than its factorization.

125663991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27585.

The product of its digits is 87480, while the sum is 42.

The square root of 125663991 is about 11209.9951382683. The cubic root of 125663991 is about 500.8837583554.

The spelling of 125663991 in words is "one hundred twenty-five million, six hundred sixty-three thousand, nine hundred ninety-one".