1581443138 has 24 divisors (see below), whose sum is σ = 2697343740. Its totient is φ = 694047200.

The previous prime is 1581443113. The next prime is 1581443141. The reversal of 1581443138 is 8313441851.

It can be written as a sum of positive squares in 2 ways, for example, as 1396292689 + 185150449 = 37367^2 + 13607^2 .

It is an unprimeable number.

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, 105653 + ... + 119688.

Almost surely, 2^1581443138 is an apocalyptic number.

1581443138 is a deficient number, since it is larger than the sum of its proper divisors (1115900602).

1581443138 is a wasteful number, since it uses less digits than its factorization.

1581443138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225394 (or 225383 counting only the distinct ones).

The product of its digits is 46080, while the sum is 38.

The square root of 1581443138 is about 39767.3627237211. The cubic root of 1581443138 is about 1165.0677846196.

Adding to 1581443138 its reverse (8313441851), we get a palindrome (9894884989).

The spelling of 1581443138 in words is "one billion, five hundred eighty-one million, four hundred forty-three thousand, one hundred thirty-eight".