81609163 has 8 divisors (see below), whose sum is σ = 86743008. Its totient is φ = 76512384.

The previous prime is 81609131. The next prime is 81609167. The reversal of 81609163 is 36190618.

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 81609163 - 2⁵ = 81609131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81609167) 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, 4656 + ... + 13597.

It is an arithmetic number, because the mean of its divisors is an integer number (10842876).

Almost surely, 2^81609163 is an apocalyptic number.

81609163 is a deficient number, since it is larger than the sum of its proper divisors (5133845).

81609163 is a wasteful number, since it uses less digits than its factorization.

81609163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18533.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 81609163 is about 9033.7789988465. The cubic root of 81609163 is about 433.7568115932.

The spelling of 81609163 in words is "eighty-one million, six hundred nine thousand, one hundred sixty-three".