1938786878391 has 32 divisors (see below), whose sum is σ = 2880160208640. Its totient is φ = 1150148908800.

The previous prime is 1938786878383. The next prime is 1938786878393.

1938786878391 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1938786878391 - 2³ = 1938786878383 is a prime.

It is a super-2 number, since 2×1938786878391² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1938786878393) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1683220 + ... + 2590521.

It is an arithmetic number, because the mean of its divisors is an integer number (90005006520).

Almost surely, 2^{1938786878391} is an apocalyptic number.

1938786878391 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1938786878391 is a deficient number, since it is larger than the sum of its proper divisors (941373330249).

1938786878391 is a wasteful number, since it uses less digits than its factorization.

1938786878391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4274047.

The product of its digits is 877879296, while the sum is 78.

The spelling of 1938786878391 in words is "one trillion, nine hundred thirty-eight billion, seven hundred eighty-six million, eight hundred seventy-eight thousand, three hundred ninety-one".