1581366873 has 4 divisors (see below), whose sum is σ = 2108489168. Its totient is φ = 1054244580.

The previous prime is 1581366859. The next prime is 1581366887. The reversal of 1581366873 is 3786631851.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3786631851 = 3 ⋅1262210617.

It is an interprime number because it is at equal distance from previous prime (1581366859) and next prime (1581366887).

It is not a de Polignac number, because 1581366873 - 2⁸ = 1581366617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1581366473) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 263561143 + ... + 263561148.

It is an arithmetic number, because the mean of its divisors is an integer number (527122292).

Almost surely, 2^1581366873 is an apocalyptic number.

It is an amenable number.

1581366873 is a deficient number, since it is larger than the sum of its proper divisors (527122295).

1581366873 is an equidigital number, since it uses as much as digits as its factorization.

1581366873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527122294.

The product of its digits is 725760, while the sum is 48.

The square root of 1581366873 is about 39766.4038228251. The cubic root of 1581366873 is about 1165.0490558773.

It can be divided in two parts, 158 and 1366873, that added together give a triangular number (1367031 = T₁₆₅₃).

The spelling of 1581366873 in words is "one billion, five hundred eighty-one million, three hundred sixty-six thousand, eight hundred seventy-three".