125691391507 has 16 divisors (see below), whose sum is σ = 143099278848. Its totient is φ = 109281775680.

The previous prime is 125691391499. The next prime is 125691391537. The reversal of 125691391507 is 705193196521.

It is a happy number.

It is not a de Polignac number, because 125691391507 - 2³ = 125691391499 is a prime.

It is not an unprimeable number, because it can be changed into a prime (125691391537) 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 15 ways as a sum of consecutive naturals, for example, 2052778 + ... + 2113120.

It is an arithmetic number, because the mean of its divisors is an integer number (8943704928).

Almost surely, 2^125691391507 is an apocalyptic number.

125691391507 is a deficient number, since it is larger than the sum of its proper divisors (17407887341).

125691391507 is a wasteful number, since it uses less digits than its factorization.

125691391507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68610.

The product of its (nonzero) digits is 510300, while the sum is 49.

The spelling of 125691391507 in words is "one hundred twenty-five billion, six hundred ninety-one million, three hundred ninety-one thousand, five hundred seven".