81349136 has 40 divisors (see below), whose sum is σ = 173137728. Its totient is φ = 36720000.

The previous prime is 81349133. The next prime is 81349139. The reversal of 81349136 is 63194318.

It is an interprime number because it is at equal distance from previous prime (81349133) and next prime (81349139).

It is a junction number, because it is equal to n+sod(n) for n = 81349096 and 81349105.

It is not an unprimeable number, because it can be changed into a prime (81349133) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25046 + ... + 28106.

Almost surely, 2^81349136 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 81349136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86568864).

81349136 is an abundant number, since it is smaller than the sum of its proper divisors (91788592).

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

81349136 is a wasteful number, since it uses less digits than its factorization.

81349136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3231 (or 3225 counting only the distinct ones).

The product of its digits is 15552, while the sum is 35.

The square root of 81349136 is about 9019.3755881436. The cubic root of 81349136 is about 433.2956359054.

The spelling of 81349136 in words is "eighty-one million, three hundred forty-nine thousand, one hundred thirty-six".