83663581 has 4 divisors (see below), whose sum is σ = 87301152. Its totient is φ = 80026012.

The previous prime is 83663563. The next prime is 83663597. The reversal of 83663581 is 18536638.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18536638 = 2 ⋅9268319.

It is a cyclic number.

It is not a de Polignac number, because 83663581 - 2⁷ = 83663453 is a prime.

It is a super-2 number, since 2×83663581² = 13999189571487122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a pancake number, because a pancake can be divided into 83663581 parts by 12935 straight cuts.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83663551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1818751 + ... + 1818796.

It is an arithmetic number, because the mean of its divisors is an integer number (21825288).

Almost surely, 2^83663581 is an apocalyptic number.

It is an amenable number.

83663581 is a deficient number, since it is larger than the sum of its proper divisors (3637571).

83663581 is a wasteful number, since it uses less digits than its factorization.

83663581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3637570.

The product of its digits is 103680, while the sum is 40.

The square root of 83663581 is about 9146.7798158696. The cubic root of 83663581 is about 437.3664676560.

The spelling of 83663581 in words is "eighty-three million, six hundred sixty-three thousand, five hundred eighty-one".