866204649 has 12 divisors (see below), whose sum is σ = 1254794736. Its totient is φ = 575803512.

The previous prime is 866204597. The next prime is 866204653. The reversal of 866204649 is 946402668.

It is not a de Polignac number, because 866204649 - 2¹⁷ = 866073577 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (866204149) 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, 135559 + ... + 141804.

It is an arithmetic number, because the mean of its divisors is an integer number (104566228).

Almost surely, 2^866204649 is an apocalyptic number.

It is an amenable number.

866204649 is a deficient number, since it is larger than the sum of its proper divisors (388590087).

866204649 is a wasteful number, since it uses less digits than its factorization.

866204649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277716 (or 277713 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 866204649 is about 29431.3548617796. The cubic root of 866204649 is about 953.2500500895.

The spelling of 866204649 in words is "eight hundred sixty-six million, two hundred four thousand, six hundred forty-nine".