816545394 has 128 divisors (see below), whose sum is σ = 2267136000. Its totient is φ = 212440320.

The previous prime is 816545393. The next prime is 816545413. The reversal of 816545394 is 493545618.

816545394 is a `hidden beast` number, since 8 + 16 + 545 + 3 + 94 = 666.

It is not an unprimeable number, because it can be changed into a prime (816545393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 197157 + ... + 201255.

It is an arithmetic number, because the mean of its divisors is an integer number (17712000).

Almost surely, 2^816545394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816545394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1133568000).

816545394 is an abundant number, since it is smaller than the sum of its proper divisors (1450590606).

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

816545394 is a wasteful number, since it uses less digits than its factorization.

816545394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4165 (or 4159 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The square root of 816545394 is about 28575.2584240283. The cubic root of 816545394 is about 934.6738904859.

The spelling of 816545394 in words is "eight hundred sixteen million, five hundred forty-five thousand, three hundred ninety-four".