81852225 has 96 divisors (see below), whose sum is σ = 169989120. Its totient is φ = 33834240.

The previous prime is 81852223. The next prime is 81852233. The reversal of 81852225 is 52225818.

It is not a de Polignac number, because 81852225 - 2¹ = 81852223 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81852223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 457186 + ... + 457364.

It is an arithmetic number, because the mean of its divisors is an integer number (1770720).

Almost surely, 2^81852225 is an apocalyptic number.

It is an amenable number.

81852225 is an abundant number, since it is smaller than the sum of its proper divisors (88136895).

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

81852225 is a wasteful number, since it uses less digits than its factorization.

81852225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279 (or 274 counting only the distinct ones).

The product of its digits is 12800, while the sum is 33.

The square root of 81852225 is about 9047.2219493058. The cubic root of 81852225 is about 434.1870136995.

The spelling of 81852225 in words is "eighty-one million, eight hundred fifty-two thousand, two hundred twenty-five".