1938768391 has 16 divisors (see below), whose sum is σ = 2290672384. Its totient is φ = 1606397184.

The previous prime is 1938768389. The next prime is 1938768397. The reversal of 1938768391 is 1938678391.

It is not a de Polignac number, because 1938768391 - 2¹ = 1938768389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1938768397) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4005 + ... + 62398.

It is an arithmetic number, because the mean of its divisors is an integer number (143167024).

Almost surely, 2^1938768391 is an apocalyptic number.

1938768391 is a deficient number, since it is larger than the sum of its proper divisors (351903993).

1938768391 is an equidigital number, since it uses as much as digits as its factorization.

1938768391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66550.

The product of its digits is 1959552, while the sum is 55.

The square root of 1938768391 is about 44031.4477504431. The cubic root of 1938768391 is about 1246.9297216336.

Subtracting from 1938768391 its reverse (1938678391), we obtain a square (90000 = 300²).

It can be divided in two parts, 19387 and 68391, that added together give a palindrome (87778).

The spelling of 1938768391 in words is "one billion, nine hundred thirty-eight million, seven hundred sixty-eight thousand, three hundred ninety-one".