812400919 has 4 divisors (see below), whose sum is σ = 886255560. Its totient is φ = 738546280.

The previous prime is 812400893. The next prime is 812400949. The reversal of 812400919 is 919004218.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-812400919 is a prime.

It is a super-2 number, since 2×812400919² = 1319990506384089122, which 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 (812400949) 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, 36927304 + ... + 36927325.

It is an arithmetic number, because the mean of its divisors is an integer number (221563890).

Almost surely, 2^812400919 is an apocalyptic number.

812400919 is a deficient number, since it is larger than the sum of its proper divisors (73854641).

812400919 is a wasteful number, since it uses less digits than its factorization.

812400919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73854640.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 812400919 is about 28502.6475787777. The cubic root of 812400919 is about 933.0898573098.

The spelling of 812400919 in words is "eight hundred twelve million, four hundred thousand, nine hundred nineteen".