77871693025 has 135 divisors (see below), whose sum is σ = 121476482169. Its totient is φ = 49506589440.

The previous prime is 77871692993. The next prime is 77871693121. The reversal of 77871693025 is 52039617877.

It is a happy number.

The square root of 77871693025 is 279055.

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 1821497041 + 76050195984 = 42679^2 + 275772^2 .

It is not a de Polignac number, because 77871693025 - 2⁵ = 77871692993 is a prime.

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, 1162264042 + ... + 1162264108.

Almost surely, 2^77871693025 is an apocalyptic number.

77871693025 is the 279055-th square number.

77871693025 is the 139528-th centered octagonal number.

It is an amenable number.

77871693025 is a deficient number, since it is larger than the sum of its proper divisors (43604789144).

77871693025 is an frugal number, since it uses more digits than its factorization.

77871693025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 4445280, while the sum is 55.

The spelling of 77871693025 in words is "seventy-seven billion, eight hundred seventy-one million, six hundred ninety-three thousand, twenty-five".