81035240 has 128 divisors (see below), whose sum is σ = 221598720. Its totient is φ = 26265600.

The previous prime is 81035239. The next prime is 81035281. The reversal of 81035240 is 4253018.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 177092 + ... + 177548.

It is an arithmetic number, because the mean of its divisors is an integer number (1731240).

Almost surely, 2^81035240 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 81035240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110799360).

81035240 is an abundant number, since it is smaller than the sum of its proper divisors (140563480).

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

81035240 is a wasteful number, since it uses less digits than its factorization.

81035240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 523 (or 519 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 81035240 is about 9001.9575648855. The cubic root of 81035240 is about 432.7376087539.

Adding to 81035240 its reverse (4253018), we get a palindrome (85288258).

The spelling of 81035240 in words is "eighty-one million, thirty-five thousand, two hundred forty".