811240 has 32 divisors (see below), whose sum is σ = 1934280. Its totient is φ = 305152.

The previous prime is 811231. The next prime is 811241. The reversal of 811240 is 42118.

811240 = T₅₁ + T₅₂ + ... + T₁₇₀.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 736164 + 75076 = 858^2 + 274^2 .

It is a super-2 number, since 2×811240² = 1316220675200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (811241) 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, 84 + ... + 1276.

2⁸¹¹²⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 811240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (967140).

811240 is an abundant number, since it is smaller than the sum of its proper divisors (1123040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

811240 is a wasteful number, since it uses less digits than its factorization.

811240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1221 (or 1217 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 811240 is about 900.6886254417. The cubic root of 811240 is about 93.2645184361.

Adding to 811240 its reverse (42118), we get a palindrome (853358).

The spelling of 811240 in words is "eight hundred eleven thousand, two hundred forty".