81411889 has 4 divisors (see below), whose sum is σ = 87674356. Its totient is φ = 75149424.

The previous prime is 81411871. The next prime is 81411907. The reversal of 81411889 is 98811418.

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 (81411871) and next prime (81411907).

It can be written as a sum of positive squares in 2 ways, for example, as 47679025 + 33732864 = 6905^2 + 5808^2 .

It is a cyclic number.

It is not a de Polignac number, because 81411889 - 2⁹ = 81411377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81411089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3131214 + ... + 3131239.

It is an arithmetic number, because the mean of its divisors is an integer number (21918589).

Almost surely, 2^81411889 is an apocalyptic number.

It is an amenable number.

81411889 is a deficient number, since it is larger than the sum of its proper divisors (6262467).

81411889 is a wasteful number, since it uses less digits than its factorization.

81411889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6262466.

The product of its digits is 18432, while the sum is 40.

The square root of 81411889 is about 9022.8537060068. The cubic root of 81411889 is about 433.4070225110.

The spelling of 81411889 in words is "eighty-one million, four hundred eleven thousand, eight hundred eighty-nine".