1931381919 has 6 divisors (see below), whose sum is σ = 2789773896. Its totient is φ = 1287587940.

The previous prime is 1931381873. The next prime is 1931381929. The reversal of 1931381919 is 9191831391.

It is a happy number.

It is not a de Polignac number, because 1931381919 - 2⁸ = 1931381663 is a prime.

It is a super-2 number, since 2×1931381919² = 7460472234080245122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1931381929) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 107298987 + ... + 107299004.

It is an arithmetic number, because the mean of its divisors is an integer number (464962316).

Almost surely, 2^1931381919 is an apocalyptic number.

1931381919 is a deficient number, since it is larger than the sum of its proper divisors (858391977).

1931381919 is a wasteful number, since it uses less digits than its factorization.

1931381919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214597997 (or 214597994 counting only the distinct ones).

The product of its digits is 52488, while the sum is 45.

The square root of 1931381919 is about 43947.4904744287. The cubic root of 1931381919 is about 1245.3441560777.

The spelling of 1931381919 in words is "one billion, nine hundred thirty-one million, three hundred eighty-one thousand, nine hundred nineteen".