81034240 has 264 divisors, whose sum is σ = 252026640. Its totient is φ = 24772608.

The previous prime is 81034237. The next prime is 81034241. The reversal of 81034240 is 4243018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81034241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4264951 + ... + 4264969.

Almost surely, 2^81034240 is an apocalyptic number.

81034240 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81034240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126013320).

81034240 is an abundant number, since it is smaller than the sum of its proper divisors (170992400).

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

81034240 is a wasteful number, since it uses less digits than its factorization.

81034240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 81034240 is about 9001.9020212397. The cubic root of 81034240 is about 432.7358287078.

Adding to 81034240 its reverse (4243018), we get a palindrome (85277258).

The spelling of 81034240 in words is "eighty-one million, thirty-four thousand, two hundred forty".