81449300 has 18 divisors (see below), whose sum is σ = 176745198. Its totient is φ = 32579680.

The previous prime is 81449293. The next prime is 81449309. The reversal of 81449300 is 394418.

It can be written as a sum of positive squares in 3 ways, for example, as 521284 + 80928016 = 722^2 + 8996^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81449309) 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 5 ways as a sum of consecutive naturals, for example, 407147 + ... + 407346.

Almost surely, 2^81449300 is an apocalyptic number.

It is an amenable number.

81449300 is an abundant number, since it is smaller than the sum of its proper divisors (95295898).

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

81449300 is a wasteful number, since it uses less digits than its factorization.

81449300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814507 (or 814500 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 81449300 is about 9024.9265924992. The cubic root of 81449300 is about 433.4733998233.

The spelling of 81449300 in words is "eighty-one million, four hundred forty-nine thousand, three hundred".