778131025 has 27 divisors (see below), whose sum is σ = 1123824369. Its totient is φ = 532906080.

The previous prime is 778131023. The next prime is 778131041. The reversal of 778131025 is 520131877.

The square root of 778131025 is 27895.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 19018321 + 759112704 = 4361^2 + 27552^2 .

It is not a de Polignac number, because 778131025 - 2¹ = 778131023 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (778131023) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 975927 + ... + 976723.

Almost surely, 2^778131025 is an apocalyptic number.

778131025 is the 27895-th square number.

778131025 is the 13948-th centered octagonal number.

It is an amenable number.

778131025 is a deficient number, since it is larger than the sum of its proper divisors (345693344).

778131025 is an frugal number, since it uses more digits than its factorization.

778131025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618 (or 809 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 34.

The cubic root of 778131025 is about 919.7805970978.

The spelling of 778131025 in words is "seven hundred seventy-eight million, one hundred thirty-one thousand, twenty-five".