181981702663 has 4 divisors (see below), whose sum is σ = 192686508720. Its totient is φ = 171276896608.

The previous prime is 181981702657. The next prime is 181981702673. The reversal of 181981702663 is 366207189181.

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 181981702663 - 2⁹ = 181981702151 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 181981702663.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181981702603) 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, 5352403003 + ... + 5352403036.

It is an arithmetic number, because the mean of its divisors is an integer number (48171627180).

Almost surely, 2^181981702663 is an apocalyptic number.

181981702663 is a deficient number, since it is larger than the sum of its proper divisors (10704806057).

181981702663 is a wasteful number, since it uses less digits than its factorization.

181981702663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10704806056.

The product of its (nonzero) digits is 870912, while the sum is 52.

The spelling of 181981702663 in words is "one hundred eighty-one billion, nine hundred eighty-one million, seven hundred two thousand, six hundred sixty-three".