81750240 has 288 divisors, whose sum is σ = 328569696. Its totient is φ = 18247680.

The previous prime is 81750233. The next prime is 81750271. The reversal of 81750240 is 4205718.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 205722 + ... + 206118.

It is an arithmetic number, because the mean of its divisors is an integer number (1140867).

Almost surely, 2^81750240 is an apocalyptic number.

81750240 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 81750240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164284848).

81750240 is an abundant number, since it is smaller than the sum of its proper divisors (246819456).

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

81750240 is a wasteful number, since it uses less digits than its factorization.

81750240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 431 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 81750240 is about 9041.5839320331. The cubic root of 81750240 is about 434.0066114929.

Adding to 81750240 its reverse (4205718), we get a palindrome (85955958).

The spelling of 81750240 in words is "eighty-one million, seven hundred fifty thousand, two hundred forty".