1872781138 has 4 divisors (see below), whose sum is σ = 2809171710. Its totient is φ = 936390568.

The previous prime is 1872781121. The next prime is 1872781147. The reversal of 1872781138 is 8311872781.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1721171169 + 151609969 = 41487^2 + 12313^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 468195283 + ... + 468195286.

Almost surely, 2^1872781138 is an apocalyptic number.

1872781138 is a deficient number, since it is larger than the sum of its proper divisors (936390572).

1872781138 is an equidigital number, since it uses as much as digits as its factorization.

1872781138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 936390571.

The product of its digits is 150528, while the sum is 46.

The square root of 1872781138 is about 43275.6413932827. The cubic root of 1872781138 is about 1232.6194287868.

The spelling of 1872781138 in words is "one billion, eight hundred seventy-two million, seven hundred eighty-one thousand, one hundred thirty-eight".