129777965 has 4 divisors (see below), whose sum is σ = 155733564. Its totient is φ = 103822368.

The previous prime is 129777953. The next prime is 129778001. The reversal of 129777965 is 569777921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 569777921 = 73 ⋅7805177.

It can be written as a sum of positive squares in 2 ways, for example, as 49603849 + 80174116 = 7043^2 + 8954^2 .

It is a cyclic number.

It is not a de Polignac number, because 129777965 - 2⁸ = 129777709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12977792 + ... + 12977801.

It is an arithmetic number, because the mean of its divisors is an integer number (38933391).

Almost surely, 2^129777965 is an apocalyptic number.

It is an amenable number.

129777965 is a deficient number, since it is larger than the sum of its proper divisors (25955599).

129777965 is an equidigital number, since it uses as much as digits as its factorization.

129777965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25955598.

The product of its digits is 1666980, while the sum is 53.

The square root of 129777965 is about 11392.0132110176. The cubic root of 129777965 is about 506.2911313429.

The spelling of 129777965 in words is "one hundred twenty-nine million, seven hundred seventy-seven thousand, nine hundred sixty-five".