843540820 has 24 divisors (see below), whose sum is σ = 1778339304. Its totient is φ = 336101376.

The previous prime is 843540779. The next prime is 843540839. The reversal of 843540820 is 28045348.

It can be written as a sum of positive squares in 4 ways, for example, as 360772036 + 482768784 = 18994^2 + 21972^2 .

It is a super-2 number, since 2×843540820² = 1423122230012544800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76917 + ... + 87196.

It is an arithmetic number, because the mean of its divisors is an integer number (74097471).

Almost surely, 2^843540820 is an apocalyptic number.

It is an amenable number.

843540820 is an abundant number, since it is smaller than the sum of its proper divisors (934798484).

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

843540820 is a wasteful number, since it uses less digits than its factorization.

843540820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164379 (or 164377 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 34.

The square root of 843540820 is about 29043.7742037773. The cubic root of 843540820 is about 944.8626919937.

The spelling of 843540820 in words is "eight hundred forty-three million, five hundred forty thousand, eight hundred twenty".