81824210 has 16 divisors (see below), whose sum is σ = 158613336. Its totient is φ = 30211968.

The previous prime is 81824201. The next prime is 81824231. The reversal of 81824210 is 1242818.

It can be written as a sum of positive squares in 4 ways, for example, as 45306361 + 36517849 = 6731^2 + 6043^2 .

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 81824210.

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 7 ways as a sum of consecutive naturals, for example, 314579 + ... + 314838.

Almost surely, 2^81824210 is an apocalyptic number.

81824210 is a deficient number, since it is larger than the sum of its proper divisors (76789126).

81824210 is a wasteful number, since it uses less digits than its factorization.

81824210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 629437.

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 81824210 is about 9045.6735514831. The cubic root of 81824210 is about 434.1374726427.

The spelling of 81824210 in words is "eighty-one million, eight hundred twenty-four thousand, two hundred ten".