840268813 has 4 divisors (see below), whose sum is σ = 846402300. Its totient is φ = 834135328.

The previous prime is 840268811. The next prime is 840268829. The reversal of 840268813 is 318862048.

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

It can be written as a sum of positive squares in 2 ways, for example, as 458730724 + 381538089 = 21418^2 + 19533^2 .

It is a cyclic number.

It is not a de Polignac number, because 840268813 - 2¹ = 840268811 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840268811) 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, 3066538 + ... + 3066811.

It is an arithmetic number, because the mean of its divisors is an integer number (211600575).

Almost surely, 2^840268813 is an apocalyptic number.

It is an amenable number.

840268813 is a deficient number, since it is larger than the sum of its proper divisors (6133487).

840268813 is a wasteful number, since it uses less digits than its factorization.

840268813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6133486.

The product of its (nonzero) digits is 73728, while the sum is 40.

The square root of 840268813 is about 28987.3905862532. The cubic root of 840268813 is about 943.6394343345.

The spelling of 840268813 in words is "eight hundred forty million, two hundred sixty-eight thousand, eight hundred thirteen".