81693432 has 96 divisors (see below), whose sum is σ = 241937280. Its totient is φ = 24791040.

The previous prime is 81693431. The next prime is 81693433. The reversal of 81693432 is 23439618.

It is an interprime number because it is at equal distance from previous prime (81693431) and next prime (81693433).

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81693431) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36868 + ... + 39020.

It is an arithmetic number, because the mean of its divisors is an integer number (2520180).

Almost surely, 2^81693432 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 81693432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120968640).

81693432 is an abundant number, since it is smaller than the sum of its proper divisors (160243848).

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

81693432 is a wasteful number, since it uses less digits than its factorization.

81693432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2213 (or 2206 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 81693432 is about 9038.4419011243. The cubic root of 81693432 is about 433.9060582277.

The spelling of 81693432 in words is "eighty-one million, six hundred ninety-three thousand, four hundred thirty-two".