1581323441 has 4 divisors (see below), whose sum is σ = 1591936500. Its totient is φ = 1570710384.

The previous prime is 1581323417. The next prime is 1581323453. The reversal of 1581323441 is 1443231851.

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

It can be written as a sum of positive squares in 2 ways, for example, as 52200625 + 1529122816 = 7225^2 + 39104^2 .

It is a cyclic number.

It is not a de Polignac number, because 1581323441 - 2⁶ = 1581323377 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1581323398 and 1581323407.

It is not an unprimeable number, because it can be changed into a prime (1581323141) 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 3 ways as a sum of consecutive naturals, for example, 5306306 + ... + 5306603.

It is an arithmetic number, because the mean of its divisors is an integer number (397984125).

Almost surely, 2^1581323441 is an apocalyptic number.

It is an amenable number.

1581323441 is a deficient number, since it is larger than the sum of its proper divisors (10613059).

1581323441 is a wasteful number, since it uses less digits than its factorization.

1581323441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10613058.

The product of its digits is 11520, while the sum is 32.

The square root of 1581323441 is about 39765.8577299673. The cubic root of 1581323441 is about 1165.0383898148.

The spelling of 1581323441 in words is "one billion, five hundred eighty-one million, three hundred twenty-three thousand, four hundred forty-one".