866640925 has 6 divisors (see below), whose sum is σ = 1074634778. Its totient is φ = 693312720.

The previous prime is 866640893. The next prime is 866640941. The reversal of 866640925 is 529046668.

It can be written as a sum of positive squares in 3 ways, for example, as 188403076 + 678237849 = 13726^2 + 26043^2 .

It is not a de Polignac number, because 866640925 - 2⁵ = 866640893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 17332794 + ... + 17332843.

Almost surely, 2^866640925 is an apocalyptic number.

It is an amenable number.

866640925 is a deficient number, since it is larger than the sum of its proper divisors (207993853).

866640925 is a wasteful number, since it uses less digits than its factorization.

866640925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34665647 (or 34665642 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 46.

The square root of 866640925 is about 29438.7656840432. The cubic root of 866640925 is about 953.4100624367.

The spelling of 866640925 in words is "eight hundred sixty-six million, six hundred forty thousand, nine hundred twenty-five".