81018097663 has 4 divisors (see below), whose sum is σ = 81429357240. Its totient is φ = 80606838088.

The previous prime is 81018097661. The next prime is 81018097717. The reversal of 81018097663 is 36679081018.

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

It is a cyclic number.

It is not a de Polignac number, because 81018097663 - 2¹ = 81018097661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81018097661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 205629493 + ... + 205629886.

It is an arithmetic number, because the mean of its divisors is an integer number (20357339310).

Almost surely, 2^81018097663 is an apocalyptic number.

81018097663 is a deficient number, since it is larger than the sum of its proper divisors (411259577).

81018097663 is a wasteful number, since it uses less digits than its factorization.

81018097663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411259576.

The product of its (nonzero) digits is 435456, while the sum is 49.

The spelling of 81018097663 in words is "eighty-one billion, eighteen million, ninety-seven thousand, six hundred sixty-three".