81608963 has 4 divisors (see below), whose sum is σ = 82726968. Its totient is φ = 80490960.

The previous prime is 81608953. The next prime is 81608981. The reversal of 81608963 is 36980618.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36980618 = 2 ⋅18490309.

It is a cyclic number.

It is not a de Polignac number, because 81608963 - 2²⁰ = 80560387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81608963.

It is not an unprimeable number, because it can be changed into a prime (81608953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 558893 + ... + 559038.

It is an arithmetic number, because the mean of its divisors is an integer number (20681742).

Almost surely, 2^81608963 is an apocalyptic number.

81608963 is a deficient number, since it is larger than the sum of its proper divisors (1118005).

81608963 is a wasteful number, since it uses less digits than its factorization.

81608963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118004.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 81608963 is about 9033.7679292751. The cubic root of 81608963 is about 433.7564572562.

The spelling of 81608963 in words is "eighty-one million, six hundred eight thousand, nine hundred sixty-three".