840513261 has 16 divisors (see below), whose sum is σ = 1322098688. Its totient is φ = 464799600.

The previous prime is 840513257. The next prime is 840513277. The reversal of 840513261 is 162315048.

It is not a de Polignac number, because 840513261 - 2² = 840513257 is a prime.

It is a Smith number, since the sum of its digits (30) 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 (840513251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 644905 + ... + 646206.

It is an arithmetic number, because the mean of its divisors is an integer number (82631168).

Almost surely, 2^840513261 is an apocalyptic number.

It is an amenable number.

840513261 is a deficient number, since it is larger than the sum of its proper divisors (481585427).

840513261 is a wasteful number, since it uses less digits than its factorization.

840513261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1291152.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 840513261 is about 28991.6067336738. The cubic root of 840513261 is about 943.7309321996.

The spelling of 840513261 in words is "eight hundred forty million, five hundred thirteen thousand, two hundred sixty-one".