81704265 has 16 divisors (see below), whose sum is σ = 131253696. Its totient is φ = 43400000.

The previous prime is 81704263. The next prime is 81704279. The reversal of 81704265 is 56240718.

It is not a de Polignac number, because 81704265 - 2¹ = 81704263 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81704263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7086 + ... + 14615.

It is an arithmetic number, because the mean of its divisors is an integer number (8203356).

Almost surely, 2^81704265 is an apocalyptic number.

It is an amenable number.

81704265 is a deficient number, since it is larger than the sum of its proper divisors (49549431).

81704265 is a wasteful number, since it uses less digits than its factorization.

81704265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21960.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 81704265 is about 9039.0411549013. The cubic root of 81704265 is about 433.9252368261.

The spelling of 81704265 in words is "eighty-one million, seven hundred four thousand, two hundred sixty-five".