399766318266 has 128 divisors (see below), whose sum is σ = 962652045312. Its totient is φ = 108265248000.

The previous prime is 399766318201. The next prime is 399766318267. The reversal of 399766318266 is 662813667993.

It is a junction number, because it is equal to n+sod(n) for n = 399766318197 and 399766318206.

It is not an unprimeable number, because it can be changed into a prime (399766318267) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 43538196 + ... + 43547376.

It is an arithmetic number, because the mean of its divisors is an integer number (7520719104).

Almost surely, 2^399766318266 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399766318266, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (481326022656).

399766318266 is an abundant number, since it is smaller than the sum of its proper divisors (562885727046).

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

399766318266 is a wasteful number, since it uses less digits than its factorization.

399766318266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9908.

The product of its digits is 105815808, while the sum is 66.

The spelling of 399766318266 in words is "three hundred ninety-nine billion, seven hundred sixty-six million, three hundred eighteen thousand, two hundred sixty-six".