81227187 has 6 divisors (see below), whose sum is σ = 117328172. Its totient is φ = 54151452.

The previous prime is 81227171. The next prime is 81227197. The reversal of 81227187 is 78172218.

It is a happy number.

It is not a de Polignac number, because 81227187 - 2⁴ = 81227171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81227117) 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 5 ways as a sum of consecutive naturals, for example, 4512613 + ... + 4512630.

Almost surely, 2^81227187 is an apocalyptic number.

81227187 is a deficient number, since it is larger than the sum of its proper divisors (36100985).

81227187 is a wasteful number, since it uses less digits than its factorization.

81227187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9025249 (or 9025246 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 81227187 is about 9012.6126622639. The cubic root of 81227187 is about 433.0790124397.

The spelling of 81227187 in words is "eighty-one million, two hundred twenty-seven thousand, one hundred eighty-seven".