665606323026 has 128 divisors (see below), whose sum is σ = 1525123814400. Its totient is φ = 215084263680.

The previous prime is 665606322991. The next prime is 665606323043. The reversal of 665606323026 is 620323606566.

665606323026 is a `hidden beast` number, since 6 + 6 + 5 + 6 + 0 + 632 + 3 + 0 + 2 + 6 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 169925620 + ... + 169929536.

It is an arithmetic number, because the mean of its divisors is an integer number (11915029800).

Almost surely, 2^665606323026 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665606323026, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (762561907200).

665606323026 is an abundant number, since it is smaller than the sum of its proper divisors (859517491374).

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

665606323026 is a wasteful number, since it uses less digits than its factorization.

665606323026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4721 (or 4715 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 45.

The spelling of 665606323026 in words is "six hundred sixty-five billion, six hundred six million, three hundred twenty-three thousand, twenty-six".