866613550440 has 64 divisors (see below), whose sum is σ = 2836189805760. Its totient is φ = 210088133120.

The previous prime is 866613550421. The next prime is 866613550447. The reversal of 866613550440 is 44055316668.

It is a self number, because there is not a number n which added to its sum of digits gives 866613550440.

It is not an unprimeable number, because it can be changed into a prime (866613550447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 328261389 + ... + 328264028.

It is an arithmetic number, because the mean of its divisors is an integer number (44315465715).

Almost surely, 2^866613550440 is an apocalyptic number.

It is an amenable number.

866613550440 is an abundant number, since it is smaller than the sum of its proper divisors (1969576255320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866613550440 is a wasteful number, since it uses less digits than its factorization.

866613550440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656525442 (or 656525438 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 48.

The spelling of 866613550440 in words is "eight hundred sixty-six billion, six hundred thirteen million, five hundred fifty thousand, four hundred forty".