81283612 has 24 divisors (see below), whose sum is σ = 148159872. Its totient is φ = 38976000.

The previous prime is 81283603. The next prime is 81283619. The reversal of 81283612 is 21638218.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81283619) 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 7 ways as a sum of consecutive naturals, for example, 11112 + ... + 16912.

It is an arithmetic number, because the mean of its divisors is an integer number (6173328).

Almost surely, 2^81283612 is an apocalyptic number.

It is an amenable number.

81283612 is a deficient number, since it is larger than the sum of its proper divisors (66876260).

81283612 is a wasteful number, since it uses less digits than its factorization.

81283612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5949 (or 5947 counting only the distinct ones).

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

The square root of 81283612 is about 9015.7424541743. The cubic root of 81283612 is about 433.1792696238.

The spelling of 81283612 in words is "eighty-one million, two hundred eighty-three thousand, six hundred twelve".