81708473 has 8 divisors (see below), whose sum is σ = 101870400. Its totient is φ = 63668880.

The previous prime is 81708461. The next prime is 81708479. The reversal of 81708473 is 37480718.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81708473 - 2⁸ = 81708217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81708479) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 530498 + ... + 530651.

It is an arithmetic number, because the mean of its divisors is an integer number (12733800).

Almost surely, 2^81708473 is an apocalyptic number.

It is an amenable number.

81708473 is a deficient number, since it is larger than the sum of its proper divisors (20161927).

81708473 is a wasteful number, since it uses less digits than its factorization.

81708473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1061167.

The product of its (nonzero) digits is 37632, while the sum is 38.

The square root of 81708473 is about 9039.2739199562. The cubic root of 81708473 is about 433.9326861559.

The spelling of 81708473 in words is "eighty-one million, seven hundred eight thousand, four hundred seventy-three".