81664154 has 16 divisors (see below), whose sum is σ = 143912160. Its totient is φ = 34264560.

The previous prime is 81664153. The next prime is 81664157. The reversal of 81664154 is 45146618.

It is not an unprimeable number, because it can be changed into a prime (81664153) 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 7 ways as a sum of consecutive naturals, for example, 142484 + ... + 143055.

It is an arithmetic number, because the mean of its divisors is an integer number (8994510).

Almost surely, 2^81664154 is an apocalyptic number.

81664154 is a deficient number, since it is larger than the sum of its proper divisors (62248006).

81664154 is a wasteful number, since it uses less digits than its factorization.

81664154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285565.

The product of its digits is 23040, while the sum is 35.

The square root of 81664154 is about 9036.8221184219. The cubic root of 81664154 is about 433.8542163631.

It can be divided in two parts, 81664 and 154, that added together give a palindrome (81818).

The spelling of 81664154 in words is "eighty-one million, six hundred sixty-four thousand, one hundred fifty-four".