81943272 has 64 divisors (see below), whose sum is σ = 230025600. Its totient is φ = 27025920.

The previous prime is 81943259. The next prime is 81943289. The reversal of 81943272 is 27234918.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18997 + ... + 22907.

It is an arithmetic number, because the mean of its divisors is an integer number (3594150).

Almost surely, 2^81943272 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 81943272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115012800).

81943272 is an abundant number, since it is smaller than the sum of its proper divisors (148082328).

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

81943272 is a wasteful number, since it uses less digits than its factorization.

81943272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4023 (or 4013 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 81943272 is about 9052.2523164128. The cubic root of 81943272 is about 434.3479410158.

It can be divided in two parts, 81943 and 272, that added together give a triangular number (82215 = T₄₀₅).

The spelling of 81943272 in words is "eighty-one million, nine hundred forty-three thousand, two hundred seventy-two".