866244820860 has 72 divisors (see below), whose sum is σ = 2691697344336. Its totient is φ = 225364504320.

The previous prime is 866244820853. The next prime is 866244820867. The reversal of 866244820860 is 68028442668.

866244820860 is a `hidden beast` number, since 8 + 6 + 624 + 4 + 8 + 2 + 0 + 8 + 6 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (866244820853) and next prime (866244820867).

It is a super-2 number, since 2×866244820860² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 866244820797 and 866244820806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866244820867) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 58681294 + ... + 58696053.

It is an arithmetic number, because the mean of its divisors is an integer number (37384685338).

Almost surely, 2^866244820860 is an apocalyptic number.

It is an amenable number.

866244820860 is an abundant number, since it is smaller than the sum of its proper divisors (1825452523476).

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

866244820860 is a wasteful number, since it uses less digits than its factorization.

866244820860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117377403 (or 117377398 counting only the distinct ones).

The product of its (nonzero) digits is 7077888, while the sum is 54.

The spelling of 866244820860 in words is "eight hundred sixty-six billion, two hundred forty-four million, eight hundred twenty thousand, eight hundred sixty".