1581485 has 4 divisors (see below), whose sum is σ = 1897788. Its totient is φ = 1265184.

The previous prime is 1581479. The next prime is 1581487. The reversal of 1581485 is 5841851.

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 320356 + 1261129 = 566^2 + 1123^2 .

It is a cyclic number.

It is not a de Polignac number, because 1581485 - 2⁴ = 1581469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1581487) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158144 + ... + 158153.

It is an arithmetic number, because the mean of its divisors is an integer number (474447).

2^1581485 is an apocalyptic number.

It is an amenable number.

1581485 is a deficient number, since it is larger than the sum of its proper divisors (316303).

1581485 is an equidigital number, since it uses as much as digits as its factorization.

1581485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316302.

The product of its digits is 6400, while the sum is 32.

The square root of 1581485 is about 1257.5710715502. The cubic root of 1581485 is about 116.5078064605.

The spelling of 1581485 in words is "one million, five hundred eighty-one thousand, four hundred eighty-five".