81282617 has 4 divisors (see below), whose sum is σ = 87535140. Its totient is φ = 75030096.

The previous prime is 81282611. The next prime is 81282637. The reversal of 81282617 is 71628218.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47596201 + 33686416 = 6899^2 + 5804^2 .

It is a cyclic number.

It is not a de Polignac number, because 81282617 - 2⁴ = 81282601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81282611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3126242 + ... + 3126267.

It is an arithmetic number, because the mean of its divisors is an integer number (21883785).

Almost surely, 2^81282617 is an apocalyptic number.

It is an amenable number.

81282617 is a deficient number, since it is larger than the sum of its proper divisors (6252523).

81282617 is a wasteful number, since it uses less digits than its factorization.

81282617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6252522.

The product of its digits is 10752, while the sum is 35.

The square root of 81282617 is about 9015.6872727485. The cubic root of 81282617 is about 433.1775020878.

The spelling of 81282617 in words is "eighty-one million, two hundred eighty-two thousand, six hundred seventeen".