816648664 has 64 divisors (see below), whose sum is σ = 1682049600. Its totient is φ = 369432576.

The previous prime is 816648661. The next prime is 816648667. The reversal of 816648664 is 466846618.

It is an interprime number because it is at equal distance from previous prime (816648661) and next prime (816648667).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816648661) 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 15 ways as a sum of consecutive naturals, for example, 1996492 + ... + 1996900.

It is an arithmetic number, because the mean of its divisors is an integer number (26282025).

Almost surely, 2^816648664 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 816648664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (841024800).

816648664 is an abundant number, since it is smaller than the sum of its proper divisors (865400936).

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

816648664 is a wasteful number, since it uses less digits than its factorization.

816648664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764 (or 760 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 49.

The square root of 816648664 is about 28577.0653496821. The cubic root of 816648664 is about 934.7132921344.

The spelling of 816648664 in words is "eight hundred sixteen million, six hundred forty-eight thousand, six hundred sixty-four".