125781787109 has 4 divisors (see below), whose sum is σ = 137216495040. Its totient is φ = 114347079180.

The previous prime is 125781787099. The next prime is 125781787133. The reversal of 125781787109 is 901787187521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 125781787109 - 2¹⁶ = 125781721573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125781787189) 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, 5717353949 + ... + 5717353970.

It is an arithmetic number, because the mean of its divisors is an integer number (34304123760).

Almost surely, 2^125781787109 is an apocalyptic number.

It is an amenable number.

125781787109 is a deficient number, since it is larger than the sum of its proper divisors (11434707931).

125781787109 is a wasteful number, since it uses less digits than its factorization.

125781787109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11434707930.

The product of its (nonzero) digits is 1975680, while the sum is 56.

The spelling of 125781787109 in words is "one hundred twenty-five billion, seven hundred eighty-one million, seven hundred eighty-seven thousand, one hundred nine".