866590844399 has 16 divisors (see below), whose sum is σ = 996793271808. Its totient is φ = 737990259552.

The previous prime is 866590844387. The next prime is 866590844443. The reversal of 866590844399 is 993448095668.

It is not a de Polignac number, because 866590844399 - 2²⁰ = 866589795823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866590844299) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13709264 + ... + 13772330.

It is an arithmetic number, because the mean of its divisors is an integer number (62299579488).

Almost surely, 2^866590844399 is an apocalyptic number.

866590844399 is a deficient number, since it is larger than the sum of its proper divisors (130202427409).

866590844399 is a wasteful number, since it uses less digits than its factorization.

866590844399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75734.

The product of its (nonzero) digits is 403107840, while the sum is 71.

The spelling of 866590844399 in words is "eight hundred sixty-six billion, five hundred ninety million, eight hundred forty-four thousand, three hundred ninety-nine".