81250728 has 32 divisors (see below), whose sum is σ = 218752800. Its totient is φ = 25000128.

The previous prime is 81250723. The next prime is 81250739. The reversal of 81250728 is 82705218.

It is not an unprimeable number, because it can be changed into a prime (81250723) 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, 129898 + ... + 130521.

It is an arithmetic number, because the mean of its divisors is an integer number (6836025).

Almost surely, 2^81250728 is an apocalyptic number.

It is an amenable number.

81250728 is an abundant number, since it is smaller than the sum of its proper divisors (137502072).

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

81250728 is a wasteful number, since it uses less digits than its factorization.

81250728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260441 (or 260437 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 81250728 is about 9013.9185707438. The cubic root of 81250728 is about 433.1208462503.

The spelling of 81250728 in words is "eighty-one million, two hundred fifty thousand, seven hundred twenty-eight".