81300312 has 96 divisors (see below), whose sum is σ = 227195280. Its totient is φ = 26254080.

The previous prime is 81300301. The next prime is 81300337. The reversal of 81300312 is 21300318.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 469858 + ... + 470030.

Almost surely, 2^81300312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81300312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113597640).

81300312 is an abundant number, since it is smaller than the sum of its proper divisors (145894968).

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

81300312 is a wasteful number, since it uses less digits than its factorization.

81300312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353 (or 346 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 81300312 is about 9016.6685643867. The cubic root of 81300312 is about 433.2089336535.

The spelling of 81300312 in words is "eighty-one million, three hundred thousand, three hundred twelve".