813212240 has 20 divisors (see below), whose sum is σ = 1890718644. Its totient is φ = 325284864.

The previous prime is 813212209. The next prime is 813212249. The reversal of 813212240 is 42212318.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 592630336 + 220581904 = 24344^2 + 14852^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×813212240² = 1322628294571635200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (813212249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5082497 + ... + 5082656.

Almost surely, 2^813212240 is an apocalyptic number.

813212240 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

813212240 is an abundant number, since it is smaller than the sum of its proper divisors (1077506404).

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

813212240 is a wasteful number, since it uses less digits than its factorization.

813212240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10165166 (or 10165160 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 813212240 is about 28516.8764067876. The cubic root of 813212240 is about 933.4003704684.

Adding to 813212240 its reverse (42212318), we get a palindrome (855424558).

The spelling of 813212240 in words is "eight hundred thirteen million, two hundred twelve thousand, two hundred forty".