81818651 has 8 divisors (see below), whose sum is σ = 82552800. Its totient is φ = 81088128.

The previous prime is 81818623. The next prime is 81818687. The reversal of 81818651 is 15681818.

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

It is a cyclic number.

It is not a de Polignac number, because 81818651 - 2¹⁰ = 81817627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81818621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62435 + ... + 63731.

It is an arithmetic number, because the mean of its divisors is an integer number (10319100).

Almost surely, 2^81818651 is an apocalyptic number.

81818651 is a deficient number, since it is larger than the sum of its proper divisors (734149).

81818651 is a wasteful number, since it uses less digits than its factorization.

81818651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1813.

The product of its digits is 15360, while the sum is 38.

The square root of 81818651 is about 9045.3662722966. The cubic root of 81818651 is about 434.1276408954.

The spelling of 81818651 in words is "eighty-one million, eight hundred eighteen thousand, six hundred fifty-one".