81069217 has 4 divisors (see below), whose sum is σ = 81476800. Its totient is φ = 80661636.

The previous prime is 81069203. The next prime is 81069221. The reversal of 81069217 is 71296018.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-81069217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81069017) 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, 203493 + ... + 203890.

It is an arithmetic number, because the mean of its divisors is an integer number (20369200).

Almost surely, 2^81069217 is an apocalyptic number.

It is an amenable number.

81069217 is a deficient number, since it is larger than the sum of its proper divisors (407583).

81069217 is a wasteful number, since it uses less digits than its factorization.

81069217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407582.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 81069217 is about 9003.8445677388. The cubic root of 81069217 is about 432.7980806806.

The spelling of 81069217 in words is "eighty-one million, sixty-nine thousand, two hundred seventeen".