81270312 has 16 divisors (see below), whose sum is σ = 203175840. Its totient is φ = 27090096.

The previous prime is 81270311. The next prime is 81270331. The reversal of 81270312 is 21307218.

It is a super-2 number, since 2×81270312² = 13209727225154688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 3386263 = 81270312 / (8 + 1 + 2 + 7 + 0 + 3 + 1 + 2).

It is not an unprimeable number, because it can be changed into a prime (81270311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1693108 + ... + 1693155.

It is an arithmetic number, because the mean of its divisors is an integer number (12698490).

Almost surely, 2^81270312 is an apocalyptic number.

It is an amenable number.

81270312 is an abundant number, since it is smaller than the sum of its proper divisors (121905528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81270312 is a wasteful number, since it uses less digits than its factorization.

81270312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3386272 (or 3386268 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 81270312 is about 9015.0048252899. The cubic root of 81270312 is about 433.1556420708.

The spelling of 81270312 in words is "eighty-one million, two hundred seventy thousand, three hundred twelve".