1987131841 has 4 divisors (see below), whose sum is σ = 1992087684. Its totient is φ = 1982176000.

The previous prime is 1987131829. The next prime is 1987131863. The reversal of 1987131841 is 1481317891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1481317891 = 9931 ⋅149161.

It can be written as a sum of positive squares in 2 ways, for example, as 1740641841 + 246490000 = 41721^2 + 15700^2 .

It is a cyclic number.

It is not a de Polignac number, because 1987131841 - 2¹⁵ = 1987099073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1987131541) 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, 2477320 + ... + 2478121.

It is an arithmetic number, because the mean of its divisors is an integer number (498021921).

Almost surely, 2^1987131841 is an apocalyptic number.

It is an amenable number.

1987131841 is a deficient number, since it is larger than the sum of its proper divisors (4955843).

1987131841 is an equidigital number, since it uses as much as digits as its factorization.

1987131841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4955842.

The product of its digits is 48384, while the sum is 43.

The square root of 1987131841 is about 44577.2569927760. The cubic root of 1987131841 is about 1257.2130897543.

The spelling of 1987131841 in words is "one billion, nine hundred eighty-seven million, one hundred thirty-one thousand, eight hundred forty-one".