1938919613 has 12 divisors (see below), whose sum is σ = 2011895028. Its totient is φ = 1868509440.

The previous prime is 1938919607. The next prime is 1938919627. The reversal of 1938919613 is 3169198391.

It can be written as a sum of positive squares in 6 ways, for example, as 249545209 + 1689374404 = 15797^2 + 41102^2 .

It is not a de Polignac number, because 1938919613 - 2²⁰ = 1937871037 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1938919693) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 513653 + ... + 517413.

It is an arithmetic number, because the mean of its divisors is an integer number (167657919).

Almost surely, 2^1938919613 is an apocalyptic number.

It is an amenable number.

1938919613 is a deficient number, since it is larger than the sum of its proper divisors (72975415).

1938919613 is an equidigital number, since it uses as much as digits as its factorization.

1938919613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4432 (or 4403 counting only the distinct ones).

The product of its digits is 314928, while the sum is 50.

The square root of 1938919613 is about 44033.1649214544. The cubic root of 1938919613 is about 1246.9621405488.

The spelling of 1938919613 in words is "one billion, nine hundred thirty-eight million, nine hundred nineteen thousand, six hundred thirteen".