81282905 has 8 divisors (see below), whose sum is σ = 106406784. Its totient is φ = 59114800.

The previous prime is 81282841. The next prime is 81282907. The reversal of 81282905 is 50928218.

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

It is not a de Polignac number, because 81282905 - 2⁶ = 81282841 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81282907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 738881 + ... + 738990.

It is an arithmetic number, because the mean of its divisors is an integer number (13300848).

Almost surely, 2^81282905 is an apocalyptic number.

It is an amenable number.

81282905 is a deficient number, since it is larger than the sum of its proper divisors (25123879).

81282905 is a wasteful number, since it uses less digits than its factorization.

81282905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1477887.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 81282905 is about 9015.7032448944. The cubic root of 81282905 is about 433.1780136977.

The spelling of 81282905 in words is "eighty-one million, two hundred eighty-two thousand, nine hundred five".