77784374007025 has 81 divisors (see below), whose sum is σ = 113929904521377. Its totient is φ = 52527798892800.

The previous prime is 77784374007013. The next prime is 77784374007059. The reversal of 77784374007025 is 52070047348777.

It is a happy number.

The square root of 77784374007025 is 8819545.

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 2957791151329 + 74826582855696 = 1719823^2 + 8650236^2 .

It is not a de Polignac number, because 77784374007025 - 2⁵ = 77784374006993 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 20681831145 + ... + 20681834905.

Almost surely, 2^{77784374007025} is an apocalyptic number.

77784374007025 is the 8819545-th square number.

77784374007025 is the 4409773-rd centered octagonal number.

It is an amenable number.

77784374007025 is a deficient number, since it is larger than the sum of its proper divisors (36145530514352).

77784374007025 is an frugal number, since it uses more digits than its factorization.

77784374007025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7680 (or 3840 counting only the distinct ones).

The product of its (nonzero) digits is 64538880, while the sum is 61.

The spelling of 77784374007025 in words is "seventy-seven trillion, seven hundred eighty-four billion, three hundred seventy-four million, seven thousand, twenty-five".