81508163 has 8 divisors (see below), whose sum is σ = 89066496. Its totient is φ = 73974600.

The previous prime is 81508127. The next prime is 81508181. The reversal of 81508163 is 36180518.

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 81508163 - 2⁶ = 81508099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81508103) 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, 1070 + ... + 12812.

It is an arithmetic number, because the mean of its divisors is an integer number (11133312).

Almost surely, 2^81508163 is an apocalyptic number.

81508163 is a deficient number, since it is larger than the sum of its proper divisors (7558333).

81508163 is a wasteful number, since it uses less digits than its factorization.

81508163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12385.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 81508163 is about 9028.1871380693. The cubic root of 81508163 is about 433.5777976943.

The spelling of 81508163 in words is "eighty-one million, five hundred eight thousand, one hundred sixty-three".