81827517 has 16 divisors (see below), whose sum is σ = 111744000. Its totient is φ = 53238192.

The previous prime is 81827483. The next prime is 81827519. The reversal of 81827517 is 71572818.

It is not a de Polignac number, because 81827517 - 2²⁴ = 65050301 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81827519) 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, 69778 + ... + 70940.

It is an arithmetic number, because the mean of its divisors is an integer number (6984000).

Almost surely, 2^81827517 is an apocalyptic number.

It is an amenable number.

81827517 is a deficient number, since it is larger than the sum of its proper divisors (29916483).

81827517 is a wasteful number, since it uses less digits than its factorization.

81827517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1712.

The product of its digits is 31360, while the sum is 39.

The square root of 81827517 is about 9045.8563442053. The cubic root of 81827517 is about 434.1433212511.

The spelling of 81827517 in words is "eighty-one million, eight hundred twenty-seven thousand, five hundred seventeen".