81945332 has 24 divisors (see below), whose sum is σ = 164176320. Its totient is φ = 35058240.

The previous prime is 81945323. The next prime is 81945337. The reversal of 81945332 is 23354918.

It is a junction number, because it is equal to n+sod(n) for n = 81945292 and 81945301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81945337) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 16232 + ... + 20672.

It is an arithmetic number, because the mean of its divisors is an integer number (6840680).

Almost surely, 2^81945332 is an apocalyptic number.

It is an amenable number.

81945332 is an abundant number, since it is smaller than the sum of its proper divisors (82230988).

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

81945332 is a wasteful number, since it uses less digits than its factorization.

81945332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5111 (or 5109 counting only the distinct ones).

The product of its digits is 25920, while the sum is 35.

The square root of 81945332 is about 9052.3660995344. The cubic root of 81945332 is about 434.3515807259.

The spelling of 81945332 in words is "eighty-one million, nine hundred forty-five thousand, three hundred thirty-two".