812305520 has 40 divisors (see below), whose sum is σ = 2033890656. Its totient is φ = 299927808.

The previous prime is 812305519. The next prime is 812305531. The reversal of 812305520 is 25503218.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 812305520.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 389492 + ... + 391571.

Almost surely, 2^812305520 is an apocalyptic number.

812305520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

812305520 is an abundant number, since it is smaller than the sum of its proper divisors (1221585136).

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

812305520 is a wasteful number, since it uses less digits than its factorization.

812305520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781089 (or 781083 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 812305520 is about 28500.9740184437. The cubic root of 812305520 is about 933.0533321074.

Adding to 812305520 its reverse (25503218), we get a palindrome (837808738).

The spelling of 812305520 in words is "eight hundred twelve million, three hundred five thousand, five hundred twenty".