801781 has 6 divisors (see below), whose sum is σ = 846582. Its totient is φ = 759240.

The previous prime is 801761. The next prime is 801791. The reversal of 801781 is 187108.

It can be written as a sum of positive squares in only one way, i.e., 731025 + 70756 = 855^2 + 266^2 .

It is not a de Polignac number, because 801781 - 2¹⁹ = 277493 is a prime.

It is a super-2 number, since 2×801781² = 1285705543922, 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 (801701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 750 + ... + 1471.

It is an arithmetic number, because the mean of its divisors is an integer number (141097).

2⁸⁰¹⁷⁸¹ is an apocalyptic number.

It is an amenable number.

801781 is a deficient number, since it is larger than the sum of its proper divisors (44801).

801781 is a wasteful number, since it uses less digits than its factorization.

801781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2259 (or 2240 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 25.

The square root of 801781 is about 895.4222467641. The cubic root of 801781 is about 92.9006145283.

Adding to 801781 its reverse (187108), we get a palindrome (988889).

The spelling of 801781 in words is "eight hundred one thousand, seven hundred eighty-one".