81012147 has 4 divisors (see below), whose sum is σ = 108016200. Its totient is φ = 54008096.

The previous prime is 81012137. The next prime is 81012163. The reversal of 81012147 is 74121018.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81012147 - 2¹² = 81008051 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (81012137) 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, 13502022 + ... + 13502027.

It is an arithmetic number, because the mean of its divisors is an integer number (27004050).

Almost surely, 2^81012147 is an apocalyptic number.

81012147 is a deficient number, since it is larger than the sum of its proper divisors (27004053).

81012147 is a wasteful number, since it uses less digits than its factorization.

81012147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27004052.

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 81012147 is about 9000.6748080352. The cubic root of 81012147 is about 432.6964984130.

The spelling of 81012147 in words is "eighty-one million, twelve thousand, one hundred forty-seven".