816599940 has 96 divisors (see below), whose sum is σ = 2477502720. Its totient is φ = 199773696.

The previous prime is 816599939. The next prime is 816599941. The reversal of 816599940 is 49995618.

It is an interprime number because it is at equal distance from previous prime (816599939) and next prime (816599941).

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (816599941) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 127126 + ... + 133394.

It is an arithmetic number, because the mean of its divisors is an integer number (25807320).

Almost surely, 2^816599940 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 816599940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1238751360).

816599940 is an abundant number, since it is smaller than the sum of its proper divisors (1660902780).

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

816599940 is a wasteful number, since it uses less digits than its factorization.

816599940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6461 (or 6459 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 51.

The square root of 816599940 is about 28576.2128351536. The cubic root of 816599940 is about 934.6947023874.

The spelling of 816599940 in words is "eight hundred sixteen million, five hundred ninety-nine thousand, nine hundred forty".