81664162 has 4 divisors (see below), whose sum is σ = 122496246. Its totient is φ = 40832080.

The previous prime is 81664157. The next prime is 81664171. The reversal of 81664162 is 26146618.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 75012921 + 6651241 = 8661^2 + 2579^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20416039 + ... + 20416042.

Almost surely, 2^81664162 is an apocalyptic number.

81664162 is a deficient number, since it is larger than the sum of its proper divisors (40832084).

81664162 is a wasteful number, since it uses less digits than its factorization.

81664162 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40832083.

The product of its digits is 13824, while the sum is 34.

The square root of 81664162 is about 9036.8225610554. The cubic root of 81664162 is about 433.8542305302.

The spelling of 81664162 in words is "eighty-one million, six hundred sixty-four thousand, one hundred sixty-two".