81862210 has 32 divisors (see below), whose sum is σ = 150967152. Its totient is φ = 31948800.

The previous prime is 81862201. The next prime is 81862211. The reversal of 81862210 is 1226818.

It can be written as a sum of positive squares in 8 ways, for example, as 77810041 + 4052169 = 8821^2 + 2013^2 .

It is not an unprimeable number, because it can be changed into a prime (81862211) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 135910 + ... + 136510.

Almost surely, 2^81862210 is an apocalyptic number.

81862210 is a deficient number, since it is larger than the sum of its proper divisors (69104942).

81862210 is a wasteful number, since it uses less digits than its factorization.

81862210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 81862210 is about 9047.7737593289. The cubic root of 81862210 is about 434.2046682025.

The spelling of 81862210 in words is "eighty-one million, eight hundred sixty-two thousand, two hundred ten".