81528200 has 48 divisors (see below), whose sum is σ = 204140580. Its totient is φ = 30101760.

The previous prime is 81528179. The next prime is 81528203. The reversal of 81528200 is 282518.

It can be written as a sum of positive squares in 6 ways, for example, as 24344356 + 57183844 = 4934^2 + 7562^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 81528200.

It is not an unprimeable number, because it can be changed into a prime (81528203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13079 + ... + 18278.

Almost surely, 2^81528200 is an apocalyptic number.

It is an amenable number.

81528200 is an abundant number, since it is smaller than the sum of its proper divisors (122612380).

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

81528200 is a wasteful number, since it uses less digits than its factorization.

81528200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31386 (or 31377 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 81528200 is about 9029.2967610994. The cubic root of 81528200 is about 433.6133233244.

The spelling of 81528200 in words is "eighty-one million, five hundred twenty-eight thousand, two hundred".