81205227 has 16 divisors (see below), whose sum is σ = 120852480. Its totient is φ = 53890056.

The previous prime is 81205211. The next prime is 81205231. The reversal of 81205227 is 72250218.

It is not a de Polignac number, because 81205227 - 2⁴ = 81205211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 81205227.

It is not an unprimeable number, because it can be changed into a prime (81205207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 723 + ... + 12764.

It is an arithmetic number, because the mean of its divisors is an integer number (7553280).

Almost surely, 2^81205227 is an apocalyptic number.

81205227 is a deficient number, since it is larger than the sum of its proper divisors (39647253).

81205227 is a wasteful number, since it uses less digits than its factorization.

81205227 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13719 (or 13713 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 81205227 is about 9011.3942872344. The cubic root of 81205227 is about 433.0399808763.

The spelling of 81205227 in words is "eighty-one million, two hundred five thousand, two hundred twenty-seven".