81386212 has 12 divisors (see below), whose sum is σ = 142886016. Its totient is φ = 40561640.

The previous prime is 81386203. The next prime is 81386251. The reversal of 81386212 is 21268318.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31468 + ... + 33955.

It is an arithmetic number, because the mean of its divisors is an integer number (11907168).

Almost surely, 2^81386212 is an apocalyptic number.

It is an amenable number.

81386212 is a deficient number, since it is larger than the sum of its proper divisors (61499804).

81386212 is a wasteful number, since it uses less digits than its factorization.

81386212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65738 (or 65736 counting only the distinct ones).

The product of its digits is 4608, while the sum is 31.

The square root of 81386212 is about 9021.4307069334. The cubic root of 81386212 is about 433.3614527446.

It can be divided in two parts, 813 and 86212, that added together give a square (87025 = 295²).

The spelling of 81386212 in words is "eighty-one million, three hundred eighty-six thousand, two hundred twelve".