866399421365 has 32 divisors (see below), whose sum is σ = 1105365385440. Its totient is φ = 649666658304.

The previous prime is 866399421341. The next prime is 866399421401. The reversal of 866399421365 is 563124993668.

It can be written as a sum of positive squares in 16 ways, for example, as 66918446596 + 799480974769 = 258686^2 + 894137^2 .

It is a cyclic number.

It is not a de Polignac number, because 866399421365 - 2²⁶ = 866332312501 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 866399421298 and 866399421307.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53509691 + ... + 53525879.

It is an arithmetic number, because the mean of its divisors is an integer number (34542668295).

Almost surely, 2^866399421365 is an apocalyptic number.

866399421365 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

866399421365 is a deficient number, since it is larger than the sum of its proper divisors (238965964075).

866399421365 is a wasteful number, since it uses less digits than its factorization.

866399421365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18761.

The product of its digits is 50388480, while the sum is 62.

The spelling of 866399421365 in words is "eight hundred sixty-six billion, three hundred ninety-nine million, four hundred twenty-one thousand, three hundred sixty-five".