66555025 has 6 divisors (see below), whose sum is σ = 82528262. Its totient is φ = 53244000.

The previous prime is 66555023. The next prime is 66555089. The reversal of 66555025 is 52055566.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 3066001 + 63489024 = 1751^2 + 7968^2 .

It is not a de Polignac number, because 66555025 - 2¹ = 66555023 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66555023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1331076 + ... + 1331125.

Almost surely, 2^66555025 is an apocalyptic number.

It is an amenable number.

66555025 is a deficient number, since it is larger than the sum of its proper divisors (15973237).

66555025 is a wasteful number, since it uses less digits than its factorization.

66555025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2662211 (or 2662206 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 34.

The square root of 66555025 is about 8158.1263167470. The cubic root of 66555025 is about 405.2536641851.

The spelling of 66555025 in words is "sixty-six million, five hundred fifty-five thousand, twenty-five".