811533820 has 48 divisors (see below), whose sum is σ = 1732671360. Its totient is φ = 319228416.

The previous prime is 811533809. The next prime is 811533823. The reversal of 811533820 is 28335118.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811533823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 462064 + ... + 463816.

It is an arithmetic number, because the mean of its divisors is an integer number (36097320).

Almost surely, 2^811533820 is an apocalyptic number.

It is an amenable number.

811533820 is an abundant number, since it is smaller than the sum of its proper divisors (921137540).

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

811533820 is a wasteful number, since it uses less digits than its factorization.

811533820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2134 (or 2132 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 811533820 is about 28487.4326677572. The cubic root of 811533820 is about 932.7577678672.

Adding to 811533820 its reverse (28335118), we get a palindrome (839868938).

The spelling of 811533820 in words is "eight hundred eleven million, five hundred thirty-three thousand, eight hundred twenty".