816581383 has 4 divisors (see below), whose sum is σ = 864615600. Its totient is φ = 768547168.

The previous prime is 816581371. The next prime is 816581399. The reversal of 816581383 is 383185618.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 816581383 - 2⁹ = 816580871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816581783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24017083 + ... + 24017116.

It is an arithmetic number, because the mean of its divisors is an integer number (216153900).

Almost surely, 2^816581383 is an apocalyptic number.

816581383 is a deficient number, since it is larger than the sum of its proper divisors (48034217).

816581383 is a wasteful number, since it uses less digits than its factorization.

816581383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48034216.

The product of its digits is 138240, while the sum is 43.

The square root of 816581383 is about 28575.8881401786. Note that the first 3 decimals coincide. The cubic root of 816581383 is about 934.6876221105.

The spelling of 816581383 in words is "eight hundred sixteen million, five hundred eighty-one thousand, three hundred eighty-three".