81736432 has 20 divisors (see below), whose sum is σ = 158540200. Its totient is φ = 40822848.

The previous prime is 81736387. The next prime is 81736433. The reversal of 81736432 is 23463718.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81736433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15694 + ... + 20242.

It is an arithmetic number, because the mean of its divisors is an integer number (7927010).

Almost surely, 2^81736432 is an apocalyptic number.

It is an amenable number.

81736432 is a deficient number, since it is larger than the sum of its proper divisors (76803768).

81736432 is a wasteful number, since it uses less digits than its factorization.

81736432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5680 (or 5674 counting only the distinct ones).

The product of its digits is 24192, while the sum is 34.

The square root of 81736432 is about 9040.8203167633. The cubic root of 81736432 is about 433.9821748645.

It can be divided in two parts, 817 and 36432, that added together give a square (37249 = 193²).

The spelling of 81736432 in words is "eighty-one million, seven hundred thirty-six thousand, four hundred thirty-two".