81412193 has 8 divisors (see below), whose sum is σ = 84760680. Its totient is φ = 78099840.

The previous prime is 81412181. The next prime is 81412211. The reversal of 81412193 is 39121418.

It can be written as a sum of positive squares in 4 ways, for example, as 4376464 + 77035729 = 2092^2 + 8777^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81412193 - 2⁶ = 81412129 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81412493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4388 + ... + 13493.

It is an arithmetic number, because the mean of its divisors is an integer number (10595085).

Almost surely, 2^81412193 is an apocalyptic number.

It is an amenable number.

81412193 is a deficient number, since it is larger than the sum of its proper divisors (3348487).

81412193 is a wasteful number, since it uses less digits than its factorization.

81412193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18067.

The product of its digits is 1728, while the sum is 29.

The square root of 81412193 is about 9022.8705521026. The cubic root of 81412193 is about 433.4075619718.

The spelling of 81412193 in words is "eighty-one million, four hundred twelve thousand, one hundred ninety-three".