81804417 has 4 divisors (see below), whose sum is σ = 109072560. Its totient is φ = 54536276.

The previous prime is 81804413. The next prime is 81804431. The reversal of 81804417 is 71440818.

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 81804417 - 2² = 81804413 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81804413) 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, 13634067 + ... + 13634072.

It is an arithmetic number, because the mean of its divisors is an integer number (27268140).

Almost surely, 2^81804417 is an apocalyptic number.

It is an amenable number.

81804417 is a deficient number, since it is larger than the sum of its proper divisors (27268143).

81804417 is a wasteful number, since it uses less digits than its factorization.

81804417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27268142.

The product of its (nonzero) digits is 7168, while the sum is 33.

The square root of 81804417 is about 9044.5794263747. The cubic root of 81804417 is about 434.1024643570.

The spelling of 81804417 in words is "eighty-one million, eight hundred four thousand, four hundred seventeen".