81097632 has 384 divisors, whose sum is σ = 313528320. Its totient is φ = 19768320.

The previous prime is 81097619. The next prime is 81097637. The reversal of 81097632 is 23679018.

81097632 is a `hidden beast` number, since 8 + 10 + 9 + 7 + 632 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (81097637) 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 63 ways as a sum of consecutive naturals, for example, 1530118 + ... + 1530170.

It is an arithmetic number, because the mean of its divisors is an integer number (816480).

Almost surely, 2^81097632 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 81097632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156764160).

81097632 is an abundant number, since it is smaller than the sum of its proper divisors (232430688).

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

81097632 is a wasteful number, since it uses less digits than its factorization.

81097632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113 (or 99 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 81097632 is about 9005.4223665523. The cubic root of 81097632 is about 432.8486404425.

The spelling of 81097632 in words is "eighty-one million, ninety-seven thousand, six hundred thirty-two".