81213112 has 16 divisors (see below), whose sum is σ = 154548360. Its totient is φ = 40000224.

The previous prime is 81213103. The next prime is 81213127. The reversal of 81213112 is 21131218.

It is a self number, because there is not a number n which added to its sum of digits gives 81213112.

It is a congruent number.

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, 75223 + ... + 76294.

Almost surely, 2^81213112 is an apocalyptic number.

It is an amenable number.

81213112 is a deficient number, since it is larger than the sum of its proper divisors (73335248).

81213112 is a wasteful number, since it uses less digits than its factorization.

81213112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151590 (or 151586 counting only the distinct ones).

The product of its digits is 96, while the sum is 19.

The square root of 81213112 is about 9011.8317782790. The cubic root of 81213112 is about 433.0539964344.

It can be divided in two parts, 812 and 13112, that added together give a square (13924 = 118²).

The spelling of 81213112 in words is "eighty-one million, two hundred thirteen thousand, one hundred twelve".