813841781 has 8 divisors (see below), whose sum is σ = 823087104. Its totient is φ = 804641040.

The previous prime is 813841753. The next prime is 813841783. The reversal of 813841781 is 187148318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 813841781 - 2²² = 809647477 is a prime.

It is a super-2 number, since 2×813841781² = 1324676889002503922, 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 (813841783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26276 + ... + 48146.

It is an arithmetic number, because the mean of its divisors is an integer number (102885888).

Almost surely, 2^813841781 is an apocalyptic number.

It is an amenable number.

813841781 is a deficient number, since it is larger than the sum of its proper divisors (9245323).

813841781 is a wasteful number, since it uses less digits than its factorization.

813841781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22291.

The product of its digits is 43008, while the sum is 41.

The square root of 813841781 is about 28527.9123140829. The cubic root of 813841781 is about 933.6411695312.

The spelling of 813841781 in words is "eight hundred thirteen million, eight hundred forty-one thousand, seven hundred eighty-one".