81750440 has 16 divisors (see below), whose sum is σ = 183938580. Its totient is φ = 32700160.

The previous prime is 81750421. The next prime is 81750463. The reversal of 81750440 is 4405718.

It can be written as a sum of positive squares in 2 ways, for example, as 73650724 + 8099716 = 8582^2 + 2846^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1021841 + ... + 1021920.

Almost surely, 2^81750440 is an apocalyptic number.

It is an amenable number.

81750440 is an abundant number, since it is smaller than the sum of its proper divisors (102188140).

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

81750440 is a wasteful number, since it uses less digits than its factorization.

81750440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2043772 (or 2043768 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 81750440 is about 9041.5949920354. The cubic root of 81750440 is about 434.0069654216.

The spelling of 81750440 in words is "eighty-one million, seven hundred fifty thousand, four hundred forty".