81081867 has 4 divisors (see below), whose sum is σ = 108109160. Its totient is φ = 54054576.

The previous prime is 81081853. The next prime is 81081881. The reversal of 81081867 is 76818018.

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

It is an interprime number because it is at equal distance from previous prime (81081853) and next prime (81081881).

It is not a de Polignac number, because 81081867 - 2¹² = 81077771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81081817) 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, 13513642 + ... + 13513647.

It is an arithmetic number, because the mean of its divisors is an integer number (27027290).

Almost surely, 2^81081867 is an apocalyptic number.

81081867 is a deficient number, since it is larger than the sum of its proper divisors (27027293).

81081867 is a wasteful number, since it uses less digits than its factorization.

81081867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27027292.

The product of its (nonzero) digits is 21504, while the sum is 39.

The square root of 81081867 is about 9004.5470180348. The cubic root of 81081867 is about 432.8205907084.

The spelling of 81081867 in words is "eighty-one million, eighty-one thousand, eight hundred sixty-seven".