81145867 has 6 divisors (see below), whose sum is σ = 89193524. Its totient is φ = 73768860.

The previous prime is 81145853. The next prime is 81145871. The reversal of 81145867 is 76854118.

It is not a de Polignac number, because 81145867 - 2¹¹ = 81143819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81145807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 335193 + ... + 335434.

Almost surely, 2^81145867 is an apocalyptic number.

81145867 is a deficient number, since it is larger than the sum of its proper divisors (8047657).

81145867 is a wasteful number, since it uses less digits than its factorization.

81145867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 670649 (or 670638 counting only the distinct ones).

The product of its digits is 53760, while the sum is 40.

The square root of 81145867 is about 9008.1000771528. The cubic root of 81145867 is about 432.9344395617.

The spelling of 81145867 in words is "eighty-one million, one hundred forty-five thousand, eight hundred sixty-seven".