81243017 has 16 divisors (see below), whose sum is σ = 88678800. Its totient is φ = 74127360.

The previous prime is 81243013. The next prime is 81243023. The reversal of 81243017 is 71034218.

It can be written as a sum of positive squares in 8 ways, for example, as 6869641 + 74373376 = 2621^2 + 8624^2 .

It is a cyclic number.

It is not a de Polignac number, because 81243017 - 2² = 81243013 is a prime.

It is a super-2 number, since 2×81243017² = 13200855622524578, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81243013) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 159359 + ... + 159867.

It is an arithmetic number, because the mean of its divisors is an integer number (5542425).

Almost surely, 2^81243017 is an apocalyptic number.

It is an amenable number.

81243017 is a deficient number, since it is larger than the sum of its proper divisors (7435783).

81243017 is a wasteful number, since it uses less digits than its factorization.

81243017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 81243017 is about 9013.4908331900. The cubic root of 81243017 is about 433.1071442172.

The spelling of 81243017 in words is "eighty-one million, two hundred forty-three thousand, seventeen".