812638744919 has 4 divisors (see below), whose sum is σ = 812646345696. Its totient is φ = 812631144144.

The previous prime is 812638744903. The next prime is 812638744937. The reversal of 812638744919 is 919447836218.

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 812638744919 - 2⁴ = 812638744903 is a prime.

It is a super-2 number, since 2×812638744919² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812638744219) 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, 3637694 + ... + 3854619.

It is an arithmetic number, because the mean of its divisors is an integer number (203161586424).

Almost surely, 2^812638744919 is an apocalyptic number.

812638744919 is a deficient number, since it is larger than the sum of its proper divisors (7600777).

812638744919 is a wasteful number, since it uses less digits than its factorization.

812638744919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7600776.

The product of its digits is 20901888, while the sum is 62.

The spelling of 812638744919 in words is "eight hundred twelve billion, six hundred thirty-eight million, seven hundred forty-four thousand, nine hundred nineteen".