18611987941 has 4 divisors (see below), whose sum is σ = 19421204832. Its totient is φ = 17802771052.

The previous prime is 18611987903. The next prime is 18611987951. The reversal of 18611987941 is 14978911681.

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.

It is not a de Polignac number, because 18611987941 - 2¹⁷ = 18611856869 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 (18611987951) 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, 404608411 + ... + 404608456.

It is an arithmetic number, because the mean of its divisors is an integer number (4855301208).

Almost surely, 2^18611987941 is an apocalyptic number.

It is an amenable number.

18611987941 is a deficient number, since it is larger than the sum of its proper divisors (809216891).

18611987941 is an equidigital number, since it uses as much as digits as its factorization.

18611987941 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 809216890.

The product of its digits is 870912, while the sum is 55.

The spelling of 18611987941 in words is "eighteen billion, six hundred eleven million, nine hundred eighty-seven thousand, nine hundred forty-one".