81349161 has 4 divisors (see below), whose sum is σ = 108465552. Its totient is φ = 54232772.

The previous prime is 81349159. The next prime is 81349171. The reversal of 81349161 is 16194318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81349161 - 2¹ = 81349159 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81349171) 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, 13558191 + ... + 13558196.

It is an arithmetic number, because the mean of its divisors is an integer number (27116388).

Almost surely, 2^81349161 is an apocalyptic number.

It is an amenable number.

81349161 is a deficient number, since it is larger than the sum of its proper divisors (27116391).

81349161 is a wasteful number, since it uses less digits than its factorization.

81349161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27116390.

The product of its digits is 5184, while the sum is 33.

The square root of 81349161 is about 9019.3769740487. The cubic root of 81349161 is about 433.2956802918.

The spelling of 81349161 in words is "eighty-one million, three hundred forty-nine thousand, one hundred sixty-one".