81409067 has 4 divisors (see below), whose sum is σ = 83394696. Its totient is φ = 79423440.

The previous prime is 81409063. The next prime is 81409117. The reversal of 81409067 is 76090418.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76090418 = 2 ⋅38045209.

It is a cyclic number.

It is not a de Polignac number, because 81409067 - 2² = 81409063 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81409063) 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, 992753 + ... + 992834.

It is an arithmetic number, because the mean of its divisors is an integer number (20848674).

Almost surely, 2^81409067 is an apocalyptic number.

81409067 is a deficient number, since it is larger than the sum of its proper divisors (1985629).

81409067 is a wasteful number, since it uses less digits than its factorization.

81409067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1985628.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 81409067 is about 9022.6973239714. The cubic root of 81409067 is about 433.4020146890.

The spelling of 81409067 in words is "eighty-one million, four hundred nine thousand, sixty-seven".