811231240 has 16 divisors (see below), whose sum is σ = 1825270380. Its totient is φ = 324492480.

The previous prime is 811231237. The next prime is 811231283. The reversal of 811231240 is 42132118.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 805764996 + 5466244 = 28386^2 + 2338^2 .

It is a super-2 number, since 2×811231240² = 1316192249503875200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10140351 + ... + 10140430.

Almost surely, 2^811231240 is an apocalyptic number.

It is an amenable number.

811231240 is an abundant number, since it is smaller than the sum of its proper divisors (1014039140).

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

811231240 is a wasteful number, since it uses less digits than its factorization.

811231240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20280792 (or 20280788 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 811231240 is about 28482.1214097546. The cubic root of 811231240 is about 932.6418273594.

Adding to 811231240 its reverse (42132118), we get a palindrome (853363358).

It can be divided in two parts, 81 and 1231240, that added together give a palindrome (1231321).

The spelling of 811231240 in words is "eight hundred eleven million, two hundred thirty-one thousand, two hundred forty".