81445932 has 72 divisors (see below), whose sum is σ = 222961200. Its totient is φ = 25707456.

The previous prime is 81445909. The next prime is 81445957. The reversal of 81445932 is 23954418.

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

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, 37944 + ... + 40032.

Almost surely, 2^81445932 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 81445932, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111480600).

81445932 is an abundant number, since it is smaller than the sum of its proper divisors (141515268).

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

81445932 is a wasteful number, since it uses less digits than its factorization.

81445932 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2140 (or 2113 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 81445932 is about 9024.7399962547. The cubic root of 81445932 is about 433.4674249058.

The spelling of 81445932 in words is "eighty-one million, four hundred forty-five thousand, nine hundred thirty-two".