66909025 has 12 divisors (see below), whose sum is σ = 87848172. Its totient is φ = 50378240.

The previous prime is 66909023. The next prime is 66909091. The reversal of 66909025 is 52090966.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 2331729 + 64577296 = 1527^2 + 8036^2 .

It is not a de Polignac number, because 66909025 - 2¹ = 66909023 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66909023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78292 + ... + 79141.

It is an arithmetic number, because the mean of its divisors is an integer number (7320681).

Almost surely, 2^66909025 is an apocalyptic number.

It is an amenable number.

66909025 is a deficient number, since it is larger than the sum of its proper divisors (20939147).

66909025 is a wasteful number, since it uses less digits than its factorization.

66909025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157460 (or 157455 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 66909025 is about 8179.7937015551. The cubic root of 66909025 is about 405.9708962612.

The spelling of 66909025 in words is "sixty-six million, nine hundred nine thousand, twenty-five".