125699876809 has 4 divisors (see below), whose sum is σ = 135369098116. Its totient is φ = 116030655504.

The previous prime is 125699876767. The next prime is 125699876821. The reversal of 125699876809 is 908678996521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 908678996521 = 194527 ⋅4671223.

It can be written as a sum of positive squares in 2 ways, for example, as 61705044025 + 63994832784 = 248405^2 + 252972^2 .

It is a cyclic number.

It is not a de Polignac number, because 125699876809 - 2¹¹ = 125699874761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125699876839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4834610634 + ... + 4834610659.

It is an arithmetic number, because the mean of its divisors is an integer number (33842274529).

Almost surely, 2^125699876809 is an apocalyptic number.

It is an amenable number.

125699876809 is a deficient number, since it is larger than the sum of its proper divisors (9669221307).

125699876809 is an equidigital number, since it uses as much as digits as its factorization.

125699876809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9669221306.

The product of its (nonzero) digits is 117573120, while the sum is 70.

The spelling of 125699876809 in words is "one hundred twenty-five billion, six hundred ninety-nine million, eight hundred seventy-six thousand, eight hundred nine".