777121587025 has 81 divisors (see below), whose sum is σ = 1137714938001. Its totient is φ = 525034097280.

The previous prime is 777121587017. The next prime is 777121587037. The reversal of 777121587025 is 520785121777.

It is a happy number.

The square root of 777121587025 is 881545.

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

777121587025 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 161718992449 + 615402594576 = 402143^2 + 784476^2 .

It is not a de Polignac number, because 777121587025 - 2³ = 777121587017 is a prime.

It is a super-2 number, since 2×777121587025² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

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, 2746012534 + ... + 2746012816.

Almost surely, 2^777121587025 is an apocalyptic number.

777121587025 is the 881545-th square number.

777121587025 is the 440773-rd centered octagonal number.

It is an amenable number.

777121587025 is a deficient number, since it is larger than the sum of its proper divisors (360593350976).

777121587025 is an frugal number, since it uses more digits than its factorization.

777121587025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768 (or 384 counting only the distinct ones).

The product of its (nonzero) digits is 1920800, while the sum is 52.

The spelling of 777121587025 in words is "seven hundred seventy-seven billion, one hundred twenty-one million, five hundred eighty-seven thousand, twenty-five".