129185977 has 2 divisors, whose sum is σ = 129185978. Its totient is φ = 129185976.

The previous prime is 129185951. The next prime is 129186017. The reversal of 129185977 is 779581921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65999376 + 63186601 = 8124^2 + 7949^2 .

It is an emirp because it is prime and its reverse (779581921) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129185977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 129185977.

It is not a weakly prime, because it can be changed into another prime (129185377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64592988 + 64592989.

It is an arithmetic number, because the mean of its divisors is an integer number (64592989).

Almost surely, 2^129185977 is an apocalyptic number.

It is an amenable number.

129185977 is a deficient number, since it is larger than the sum of its proper divisors (1).

129185977 is an equidigital number, since it uses as much as digits as its factorization.

129185977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 317520, while the sum is 49.

The square root of 129185977 is about 11366.0009238078. Note that the first 3 decimals coincide. The cubic root of 129185977 is about 505.5201346158.

The spelling of 129185977 in words is "one hundred twenty-nine million, one hundred eighty-five thousand, nine hundred seventy-seven".