81663283 has 4 divisors (see below), whose sum is σ = 87945088. Its totient is φ = 75381480.

The previous prime is 81663227. The next prime is 81663287. The reversal of 81663283 is 38236618.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81663283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81663287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3140883 + ... + 3140908.

It is an arithmetic number, because the mean of its divisors is an integer number (21986272).

Almost surely, 2^81663283 is an apocalyptic number.

81663283 is a deficient number, since it is larger than the sum of its proper divisors (6281805).

81663283 is a wasteful number, since it uses less digits than its factorization.

81663283 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6281804.

The product of its digits is 41472, while the sum is 37.

The square root of 81663283 is about 9036.7739265736. The cubic root of 81663283 is about 433.8526739141.

It can be divided in two parts, 8166 and 3283, that added together give a square (11449 = 107²).

The spelling of 81663283 in words is "eighty-one million, six hundred sixty-three thousand, two hundred eighty-three".