125128779 has 4 divisors (see below), whose sum is σ = 166838376. Its totient is φ = 83419184.

The previous prime is 125128777. The next prime is 125128807. The reversal of 125128779 is 977821521.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 125128779 - 2¹ = 125128777 is a prime.

It is a super-2 number, since 2×125128779² = 31314422668061682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 125128779.

It is not an unprimeable number, because it can be changed into a prime (125128777) 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, 20854794 + ... + 20854799.

It is an arithmetic number, because the mean of its divisors is an integer number (41709594).

Almost surely, 2^125128779 is an apocalyptic number.

125128779 is a deficient number, since it is larger than the sum of its proper divisors (41709597).

125128779 is an equidigital number, since it uses as much as digits as its factorization.

125128779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41709596.

The product of its digits is 70560, while the sum is 42.

The square root of 125128779 is about 11186.0975769032. The cubic root of 125128779 is about 500.1716464016.

The spelling of 125128779 in words is "one hundred twenty-five million, one hundred twenty-eight thousand, seven hundred seventy-nine".