81785427 has 8 divisors (see below), whose sum is σ = 109097616. Its totient is φ = 54498432.

The previous prime is 81785377. The next prime is 81785449. The reversal of 81785427 is 72458718.

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

It is not a de Polignac number, because 81785427 - 2¹² = 81781331 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81785467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3423 + ... + 13239.

It is an arithmetic number, because the mean of its divisors is an integer number (13637202).

Almost surely, 2^81785427 is an apocalyptic number.

81785427 is a deficient number, since it is larger than the sum of its proper divisors (27312189).

81785427 is a wasteful number, since it uses less digits than its factorization.

81785427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12597.

The product of its digits is 125440, while the sum is 42.

The square root of 81785427 is about 9043.5295653854. The cubic root of 81785427 is about 434.0688710456.

The spelling of 81785427 in words is "eighty-one million, seven hundred eighty-five thousand, four hundred twenty-seven".