1581201 has 18 divisors (see below), whose sum is σ = 2381522. Its totient is φ = 1049760.

The previous prime is 1581193. The next prime is 1581211. The reversal of 1581201 is 1021851.

It can be written as a sum of positive squares in only one way, i.e., 1476225 + 104976 = 1215^2 + 324^2 .

It is not a de Polignac number, because 1581201 - 2³ = 1581193 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (1581211) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 6441 + ... + 6681.

2^1581201 is an apocalyptic number.

It is an amenable number.

1581201 is a deficient number, since it is larger than the sum of its proper divisors (800321).

1581201 is an frugal number, since it uses more digits than its factorization.

1581201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 1581201 is about 1257.4581503971. The cubic root of 1581201 is about 116.5008319612.

The spelling of 1581201 in words is "one million, five hundred eighty-one thousand, two hundred one".