866409988 has 6 divisors (see below), whose sum is σ = 1516217486. Its totient is φ = 433204992.

The previous prime is 866409983. The next prime is 866409989. The reversal of 866409988 is 889904668.

It can be written as a sum of positive squares in only one way, i.e., 439657024 + 426752964 = 20968^2 + 20658^2 .

It is not an unprimeable number, because it can be changed into a prime (866409983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108301245 + ... + 108301252.

Almost surely, 2^866409988 is an apocalyptic number.

It is an amenable number.

866409988 is a deficient number, since it is larger than the sum of its proper divisors (649807498).

866409988 is a wasteful number, since it uses less digits than its factorization.

866409988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216602501 (or 216602499 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 58.

The square root of 866409988 is about 29434.8430945368. The cubic root of 866409988 is about 953.3253686828.

The spelling of 866409988 in words is "eight hundred sixty-six million, four hundred nine thousand, nine hundred eighty-eight".