866644206405 has 32 divisors (see below), whose sum is σ = 1468254584448. Its totient is φ = 435004416000.

The previous prime is 866644206403. The next prime is 866644206431. The reversal of 866644206405 is 504602446668.

It is not a de Polignac number, because 866644206405 - 2¹ = 866644206403 is a prime.

It is a super-3 number, since 3×866644206405³ (a number of 37 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866644206403) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8786965 + ... + 8885045.

It is an arithmetic number, because the mean of its divisors is an integer number (45882955764).

Almost surely, 2^866644206405 is an apocalyptic number.

866644206405 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

866644206405 is a deficient number, since it is larger than the sum of its proper divisors (601610378043).

866644206405 is a wasteful number, since it uses less digits than its factorization.

866644206405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132757.

The product of its (nonzero) digits is 6635520, while the sum is 51.

The spelling of 866644206405 in words is "eight hundred sixty-six billion, six hundred forty-four million, two hundred six thousand, four hundred five".