19870890841 has 4 divisors (see below), whose sum is σ = 19871337892. Its totient is φ = 19870443792.

The previous prime is 19870890833. The next prime is 19870890847. The reversal of 19870890841 is 14809807891.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10233345600 + 9637545241 = 101160^2 + 98171^2 .

It is a cyclic number.

It is not a de Polignac number, because 19870890841 - 2³ = 19870890833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19870890847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148446 + ... + 248551.

It is an arithmetic number, because the mean of its divisors is an integer number (4967834473).

Almost surely, 2^19870890841 is an apocalyptic number.

It is an amenable number.

19870890841 is a deficient number, since it is larger than the sum of its proper divisors (447051).

19870890841 is an equidigital number, since it uses as much as digits as its factorization.

19870890841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 447050.

The product of its (nonzero) digits is 1161216, while the sum is 55.

The spelling of 19870890841 in words is "nineteen billion, eight hundred seventy million, eight hundred ninety thousand, eight hundred forty-one".