665690850 has 144 divisors (see below), whose sum is σ = 1964499264. Its totient is φ = 160272000.

The previous prime is 665690813. The next prime is 665690867. The reversal of 665690850 is 58096566.

665690850 is a `hidden beast` number, since 6 + 6 + 569 + 0 + 85 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 665690796 and 665690805.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 895579 + ... + 896321.

It is an arithmetic number, because the mean of its divisors is an integer number (13642356).

Almost surely, 2^665690850 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665690850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (982249632).

665690850 is an abundant number, since it is smaller than the sum of its proper divisors (1298808414).

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

665690850 is a wasteful number, since it uses less digits than its factorization.

665690850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 953 (or 945 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 665690850 is about 25800.9854462964. The cubic root of 665690850 is about 873.1540294186.

The spelling of 665690850 in words is "six hundred sixty-five million, six hundred ninety thousand, eight hundred fifty".