1916871381 has 12 divisors (see below), whose sum is σ = 2814205420. Its totient is φ = 1256964480.

The previous prime is 1916871371. The next prime is 1916871403. The reversal of 1916871381 is 1831786191.

1916871381 is a `hidden beast` number, since 191 + 6 + 87 + 1 + 381 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 220255281 + 1696616100 = 14841^2 + 41190^2 .

It is not a de Polignac number, because 1916871381 - 2⁵ = 1916871349 is a prime.

It is a super-2 number, since 2×1916871381² = 7348791782593694322, which contains 22 as substring.

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 (1916871311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1745236 + ... + 1746333.

Almost surely, 2^1916871381 is an apocalyptic number.

It is an amenable number.

1916871381 is a deficient number, since it is larger than the sum of its proper divisors (897334039).

1916871381 is a wasteful number, since it uses less digits than its factorization.

1916871381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3491636 (or 3491633 counting only the distinct ones).

The product of its digits is 72576, while the sum is 45.

The square root of 1916871381 is about 43782.0897285637. The cubic root of 1916871381 is about 1242.2175418457.

The spelling of 1916871381 in words is "one billion, nine hundred sixteen million, eight hundred seventy-one thousand, three hundred eighty-one".