81725705 has 8 divisors (see below), whose sum is σ = 98210112. Its totient is φ = 65287728.

The previous prime is 81725627. The next prime is 81725747. The reversal of 81725705 is 50752718.

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

It is a cyclic number.

It is not a de Polignac number, because 81725705 - 2¹² = 81721609 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7607 + ... + 14876.

It is an arithmetic number, because the mean of its divisors is an integer number (12276264).

Almost surely, 2^81725705 is an apocalyptic number.

It is an amenable number.

81725705 is a deficient number, since it is larger than the sum of its proper divisors (16484407).

81725705 is a wasteful number, since it uses less digits than its factorization.

81725705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23215.

The product of its (nonzero) digits is 19600, while the sum is 35.

The square root of 81725705 is about 9040.2270436090. The cubic root of 81725705 is about 433.9631889184.

The spelling of 81725705 in words is "eighty-one million, seven hundred twenty-five thousand, seven hundred five".