816488640 has 448 divisors, whose sum is σ = 3212835840. Its totient is φ = 195148800.

The previous prime is 816488609. The next prime is 816488671. The reversal of 816488640 is 46884618.

It is an interprime number because it is at equal distance from previous prime (816488609) and next prime (816488671).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11499805 + ... + 11499875.

Almost surely, 2^816488640 is an apocalyptic number.

816488640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816488640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1606417920).

816488640 is an abundant number, since it is smaller than the sum of its proper divisors (2396347200).

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

816488640 is a wasteful number, since it uses less digits than its factorization.

816488640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 45.

The square root of 816488640 is about 28574.2653448868. The cubic root of 816488640 is about 934.6522351432.

The spelling of 816488640 in words is "eight hundred sixteen million, four hundred eighty-eight thousand, six hundred forty".