81109632 has 64 divisors (see below), whose sum is σ = 226807200. Its totient is φ = 25611264.

The previous prime is 81109627. The next prime is 81109649. The reversal of 81109632 is 23690118.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 81109632.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1738 + ... + 12854.

Almost surely, 2^81109632 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 81109632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113403600).

81109632 is an abundant number, since it is smaller than the sum of its proper divisors (145697568).

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

81109632 is a wasteful number, since it uses less digits than its factorization.

81109632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11153 (or 11141 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 81109632 is about 9006.0886071590. The cubic root of 81109632 is about 432.8699888977.

The spelling of 81109632 in words is "eighty-one million, one hundred nine thousand, six hundred thirty-two".