81383632 has 60 divisors (see below), whose sum is σ = 175211008. Its totient is φ = 36590400.

The previous prime is 81383611. The next prime is 81383639. The reversal of 81383632 is 23638318.

It is a super-2 number, since 2×81383632² = 13246591115022848, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81383639) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 245707 + ... + 246037.

Almost surely, 2^81383632 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 81383632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87605504).

81383632 is an abundant number, since it is smaller than the sum of its proper divisors (93827376).

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

81383632 is a wasteful number, since it uses less digits than its factorization.

81383632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488 (or 471 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 81383632 is about 9021.2877129598. The cubic root of 81383632 is about 433.3568734089.

The spelling of 81383632 in words is "eighty-one million, three hundred eighty-three thousand, six hundred thirty-two".