810813520 has 40 divisors (see below), whose sum is σ = 2056520160. Its totient is φ = 294840960.

The previous prime is 810813517. The next prime is 810813529. The reversal of 810813520 is 25318018.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (810813529) 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, 459810 + ... + 461569.

It is an arithmetic number, because the mean of its divisors is an integer number (51413004).

Almost surely, 2^810813520 is an apocalyptic number.

810813520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

810813520 is an abundant number, since it is smaller than the sum of its proper divisors (1245706640).

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

810813520 is a wasteful number, since it uses less digits than its factorization.

810813520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921403 (or 921397 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 810813520 is about 28474.7874443340. The cubic root of 810813520 is about 932.4817209219.

The spelling of 810813520 in words is "eight hundred ten million, eight hundred thirteen thousand, five hundred twenty".