1881881666563 has 4 divisors (see below), whose sum is σ = 1927781219448. Its totient is φ = 1835982113680.

The previous prime is 1881881666513. The next prime is 1881881666579. The reversal of 1881881666563 is 3656661881881.

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 1881881666563 - 2¹⁷ = 1881881535491 is a prime.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1881881666513) 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, 22949776381 + ... + 22949776462.

It is an arithmetic number, because the mean of its divisors is an integer number (481945304862).

Almost surely, 2^{1881881666563} is an apocalyptic number.

1881881666563 is a deficient number, since it is larger than the sum of its proper divisors (45899552885).

1881881666563 is an equidigital number, since it uses as much as digits as its factorization.

1881881666563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45899552884.

The product of its digits is 79626240, while the sum is 67.

The spelling of 1881881666563 in words is "one trillion, eight hundred eighty-one billion, eight hundred eighty-one million, six hundred sixty-six thousand, five hundred sixty-three".