66814495225 has 27 divisors (see below), whose sum is σ = 88039130791. Its totient is φ = 50290841600.

The previous prime is 66814495217. The next prime is 66814495249. The reversal of 66814495225 is 52259441866.

The square root of 66814495225 is 258485.

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

It can be written as a sum of positive squares in 13 ways, for example, as 4652649 + 66809842576 = 2157^2 + 258476^2 .

It is not a de Polignac number, because 66814495225 - 2³ = 66814495217 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 21969705 + ... + 21972745.

Almost surely, 2^66814495225 is an apocalyptic number.

66814495225 is the 258485-th square number.

66814495225 is the 129243-rd centered octagonal number.

It is an amenable number.

66814495225 is a deficient number, since it is larger than the sum of its proper divisors (21224635566).

66814495225 is an frugal number, since it uses more digits than its factorization.

66814495225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6126 (or 3063 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 52.

The spelling of 66814495225 in words is "sixty-six billion, eight hundred fourteen million, four hundred ninety-five thousand, two hundred twenty-five".