19981310390513 has 4 divisors (see below), whose sum is σ = 20055590355060. Its totient is φ = 19907030425968.

The previous prime is 19981310390413. The next prime is 19981310390537. The reversal of 19981310390513 is 31509301318991.

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 2310241922704 + 17671068467809 = 1519948^2 + 4203697^2 .

It is a cyclic number.

It is not a de Polignac number, because 19981310390513 - 2⁴⁰ = 18881798762737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19981310390543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37139981870 + ... + 37139982407.

It is an arithmetic number, because the mean of its divisors is an integer number (5013897588765).

Almost surely, 2^{19981310390513} is an apocalyptic number.

It is an amenable number.

19981310390513 is a deficient number, since it is larger than the sum of its proper divisors (74279964547).

19981310390513 is an equidigital number, since it uses as much as digits as its factorization.

19981310390513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74279964546.

The product of its (nonzero) digits is 787320, while the sum is 53.

The spelling of 19981310390513 in words is "nineteen trillion, nine hundred eighty-one billion, three hundred ten million, three hundred ninety thousand, five hundred thirteen".