678078137025 has 135 divisors (see below), whose sum is σ = 1302904984953. Its totient is φ = 348617908800.

The previous prime is 678078136993. The next prime is 678078137053. The reversal of 678078137025 is 520731870876.

The square root of 678078137025 is 823455.

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 9320550849 + 668757586176 = 96543^2 + 817776^2 .

It is a tau number, because it is divible by the number of its divisors (135).

It is not a de Polignac number, because 678078137025 - 2⁵ = 678078136993 is a prime.

It is a super-2 number, since 2×678078137025² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 1074608460 + ... + 1074609090.

Almost surely, 2^678078137025 is an apocalyptic number.

678078137025 is the 823455-th square number.

678078137025 is the 411728-th centered octagonal number.

It is an amenable number.

678078137025 is a deficient number, since it is larger than the sum of its proper divisors (624826847928).

678078137025 is an frugal number, since it uses more digits than its factorization.

678078137025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1342 (or 668 counting only the distinct ones).

The product of its (nonzero) digits is 3951360, while the sum is 54.

The spelling of 678078137025 in words is "six hundred seventy-eight billion, seventy-eight million, one hundred thirty-seven thousand, twenty-five".