81518633 has 16 divisors (see below), whose sum is σ = 95944704. Its totient is φ = 67813200.

The previous prime is 81518627. The next prime is 81518641. The reversal of 81518633 is 33681518.

It is not a de Polignac number, because 81518633 - 2⁴ = 81518617 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81518593 and 81518602.

It is not an unprimeable number, because it can be changed into a prime (81518603) 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 15 ways as a sum of consecutive naturals, for example, 40808 + ... + 42758.

It is an arithmetic number, because the mean of its divisors is an integer number (5996544).

Almost surely, 2^81518633 is an apocalyptic number.

It is an amenable number.

81518633 is a deficient number, since it is larger than the sum of its proper divisors (14426071).

81518633 is a wasteful number, since it uses less digits than its factorization.

81518633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2132.

The product of its digits is 17280, while the sum is 35.

The square root of 81518633 is about 9028.7669700796. The cubic root of 81518633 is about 433.5963617457.

The spelling of 81518633 in words is "eighty-one million, five hundred eighteen thousand, six hundred thirty-three".