129778025 has 24 divisors (see below), whose sum is σ = 174285720. Its totient is φ = 95293440.

The previous prime is 129778001. The next prime is 129778027. The reversal of 129778025 is 520877921.

It can be written as a sum of positive squares in 12 ways, for example, as 98148649 + 31629376 = 9907^2 + 5624^2 .

It is a de Polignac number, because none of the positive numbers 2^k-129778025 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129778027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61691 + ... + 63759.

It is an arithmetic number, because the mean of its divisors is an integer number (7261905).

Almost surely, 2^129778025 is an apocalyptic number.

It is an amenable number.

129778025 is a deficient number, since it is larger than the sum of its proper divisors (44507695).

129778025 is a wasteful number, since it uses less digits than its factorization.

129778025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2285 (or 2280 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 129778025 is about 11392.0158444412. The cubic root of 129778025 is about 506.2912093671.

The spelling of 129778025 in words is "one hundred twenty-nine million, seven hundred seventy-eight thousand, twenty-five".