81803880 has 48 divisors (see below), whose sum is σ = 265863780. Its totient is φ = 21814272.

The previous prime is 81803879. The next prime is 81803903. The reversal of 81803880 is 8830818.

It can be written as a sum of positive squares in 2 ways, for example, as 71267364 + 10536516 = 8442^2 + 3246^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 113257 + ... + 113976.

Almost surely, 2^81803880 is an apocalyptic number.

It is an amenable number.

81803880 is an abundant number, since it is smaller than the sum of its proper divisors (184059900).

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

81803880 is a wasteful number, since it uses less digits than its factorization.

81803880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227250 (or 227243 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 81803880 is about 9044.5497400368. The cubic root of 81803880 is about 434.1015144754.

The spelling of 81803880 in words is "eighty-one million, eight hundred three thousand, eight hundred eighty".