81818554 has 16 divisors (see below), whose sum is σ = 125582400. Its totient is φ = 39968320.

The previous prime is 81818537. The next prime is 81818557. The reversal of 81818554 is 45581818.

It is not an unprimeable number, because it can be changed into a prime (81818557) 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, 13497 + ... + 18595.

It is an arithmetic number, because the mean of its divisors is an integer number (7848900).

Almost surely, 2^81818554 is an apocalyptic number.

81818554 is a deficient number, since it is larger than the sum of its proper divisors (43763846).

81818554 is a wasteful number, since it uses less digits than its factorization.

81818554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5285.

The product of its digits is 51200, while the sum is 40.

The square root of 81818554 is about 9045.3609104336. The cubic root of 81818554 is about 434.1274693355.

The spelling of 81818554 in words is "eighty-one million, eight hundred eighteen thousand, five hundred fifty-four".