817001640 has 640 divisors, whose sum is σ = 3600495360. Its totient is φ = 161243136.

The previous prime is 817001597. The next prime is 817001641. The reversal of 817001640 is 46100718.

It is a happy number.

817001640 is a `hidden beast` number, since 8 + 17 + 0 + 0 + 1 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (817001641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 5012199 + ... + 5012361.

It is an arithmetic number, because the mean of its divisors is an integer number (5625774).

Almost surely, 2^817001640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 817001640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1800247680).

817001640 is an abundant number, since it is smaller than the sum of its proper divisors (2783493720).

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

817001640 is a wasteful number, since it uses less digits than its factorization.

817001640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 817001640 is about 28583.2405440671. The cubic root of 817001640 is about 934.8479415661.

The spelling of 817001640 in words is "eight hundred seventeen million, one thousand, six hundred forty".