811781841 has 64 divisors (see below), whose sum is σ = 1288175616. Its totient is φ = 449971200.

The previous prime is 811781753. The next prime is 811781879. The reversal of 811781841 is 148187118.

It is not a de Polignac number, because 811781841 - 2¹³ = 811773649 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 811781841.

It is not an unprimeable number, because it can be changed into a prime (811781881) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2610076 + ... + 2610386.

It is an arithmetic number, because the mean of its divisors is an integer number (20127744).

Almost surely, 2^811781841 is an apocalyptic number.

It is an amenable number.

811781841 is a deficient number, since it is larger than the sum of its proper divisors (476393775).

811781841 is a wasteful number, since it uses less digits than its factorization.

811781841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502.

The product of its digits is 14336, while the sum is 39.

The square root of 811781841 is about 28491.7855003859. The cubic root of 811781841 is about 932.8527813446.

The spelling of 811781841 in words is "eight hundred eleven million, seven hundred eighty-one thousand, eight hundred forty-one".