1581121 has 8 divisors (see below), whose sum is σ = 1640384. Its totient is φ = 1522800.

The previous prime is 1581113. The next prime is 1581131. The reversal of 1581121 is 1211851.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1581121 - 2³ = 1581113 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1581101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5446 + ... + 5728.

It is an arithmetic number, because the mean of its divisors is an integer number (205048).

2^1581121 is an apocalyptic number.

It is an amenable number.

1581121 is a deficient number, since it is larger than the sum of its proper divisors (59263).

1581121 is a wasteful number, since it uses less digits than its factorization.

1581121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471.

The product of its digits is 80, while the sum is 19.

The square root of 1581121 is about 1257.4263397909. The cubic root of 1581121 is about 116.4988671628.

Adding to 1581121 its reverse (1211851), we get a palindrome (2792972).

The spelling of 1581121 in words is "one million, five hundred eighty-one thousand, one hundred twenty-one".