129778513 has 4 divisors (see below), whose sum is σ = 129919140. Its totient is φ = 129637888.

The previous prime is 129778487. The next prime is 129778529. The reversal of 129778513 is 315877921.

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

It can be written as a sum of positive squares in 2 ways, for example, as 38155329 + 91623184 = 6177^2 + 9572^2 .

It is a cyclic number.

It is not a de Polignac number, because 129778513 - 2⁹ = 129778001 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 129778513.

It is not an unprimeable number, because it can be changed into a prime (129778543) 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, 68920 + ... + 70777.

It is an arithmetic number, because the mean of its divisors is an integer number (32479785).

Almost surely, 2^129778513 is an apocalyptic number.

It is an amenable number.

129778513 is a deficient number, since it is larger than the sum of its proper divisors (140627).

129778513 is an equidigital number, since it uses as much as digits as its factorization.

129778513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140626.

The product of its digits is 105840, while the sum is 43.

The square root of 129778513 is about 11392.0372629306. The cubic root of 129778513 is about 506.2918439629.

The spelling of 129778513 in words is "one hundred twenty-nine million, seven hundred seventy-eight thousand, five hundred thirteen".