66787222799025 has 81 divisors (see below), whose sum is σ = 123897113719041. Its totient is φ = 34389750790080.

The previous prime is 66787222798991. The next prime is 66787222799041. The reversal of 66787222799025 is 52099722278766.

The square root of 66787222799025 is 8172345.

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

66787222799025 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 918026510769 + 65869196288256 = 958137^2 + 8115984^2 .

It is not a de Polignac number, because 66787222799025 - 2²⁹ = 66786685928113 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 3554960682 + ... + 3554979468.

Almost surely, 2^{66787222799025} is an apocalyptic number.

66787222799025 is the 8172345-th square number.

66787222799025 is the 4086173-rd centered octagonal number.

It is an amenable number.

66787222799025 is a deficient number, since it is larger than the sum of its proper divisors (57109890920016).

66787222799025 is an frugal number, since it uses more digits than its factorization.

66787222799025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37648 (or 18824 counting only the distinct ones).

The product of its (nonzero) digits is 640120320, while the sum is 72.

The spelling of 66787222799025 in words is "sixty-six trillion, seven hundred eighty-seven billion, two hundred twenty-two million, seven hundred ninety-nine thousand, twenty-five".