81201844 has 12 divisors (see below), whose sum is σ = 142222500. Its totient is φ = 40566848.

The previous prime is 81201833. The next prime is 81201847. The reversal of 81201844 is 44810218.

It can be written as a sum of positive squares in 2 ways, for example, as 28494244 + 52707600 = 5338^2 + 7260^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81201847) 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 3 ways as a sum of consecutive naturals, for example, 2719 + ... + 13030.

It is an arithmetic number, because the mean of its divisors is an integer number (11851875).

Almost surely, 2^81201844 is an apocalyptic number.

It is an amenable number.

81201844 is a deficient number, since it is larger than the sum of its proper divisors (61020656).

81201844 is a wasteful number, since it uses less digits than its factorization.

81201844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17042 (or 17040 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 28.

The square root of 81201844 is about 9011.2065784777. The cubic root of 81201844 is about 433.0339673282.

The spelling of 81201844 in words is "eighty-one million, two hundred one thousand, eight hundred forty-four".