816412391 has 4 divisors (see below), whose sum is σ = 824495784. Its totient is φ = 808329000.

The previous prime is 816412367. The next prime is 816412417. The reversal of 816412391 is 193214618.

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 816412391 - 2⁶ = 816412327 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 (816412351) 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 3 ways as a sum of consecutive naturals, for example, 4041545 + ... + 4041746.

It is an arithmetic number, because the mean of its divisors is an integer number (206123946).

Almost surely, 2^816412391 is an apocalyptic number.

816412391 is a deficient number, since it is larger than the sum of its proper divisors (8083393).

816412391 is a wasteful number, since it uses less digits than its factorization.

816412391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8083392.

The product of its digits is 10368, while the sum is 35.

The square root of 816412391 is about 28572.9310887070. The cubic root of 816412391 is about 934.6231396101.

The spelling of 816412391 in words is "eight hundred sixteen million, four hundred twelve thousand, three hundred ninety-one".