840398743 has 4 divisors (see below), whose sum is σ = 869378040. Its totient is φ = 811419448.

The previous prime is 840398731. The next prime is 840398753. The reversal of 840398743 is 347893048.

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 840398743 - 2⁹ = 840398231 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 840398693 and 840398702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840398753) 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, 14489605 + ... + 14489662.

It is an arithmetic number, because the mean of its divisors is an integer number (217344510).

Almost surely, 2^840398743 is an apocalyptic number.

840398743 is a deficient number, since it is larger than the sum of its proper divisors (28979297).

840398743 is a wasteful number, since it uses less digits than its factorization.

840398743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28979296.

The product of its (nonzero) digits is 580608, while the sum is 46.

The square root of 840398743 is about 28989.6316465042. The cubic root of 840398743 is about 943.6880698627.

The spelling of 840398743 in words is "eight hundred forty million, three hundred ninety-eight thousand, seven hundred forty-three".