1538561 has 6 divisors (see below), whose sum is σ = 1590786. Its totient is φ = 1488000.

The previous prime is 1538531. The next prime is 1538569. The reversal of 1538561 is 1658351.

It can be written as a sum of positive squares in only one way, i.e., 1537600 + 961 = 1240^2 + 31^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1538561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1538569) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 161 + ... + 1761.

It is an arithmetic number, because the mean of its divisors is an integer number (265131).

2^1538561 is an apocalyptic number.

It is an amenable number.

1538561 is a deficient number, since it is larger than the sum of its proper divisors (52225).

1538561 is an equidigital number, since it uses as much as digits as its factorization.

1538561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1663 (or 1632 counting only the distinct ones).

The product of its digits is 3600, while the sum is 29.

The square root of 1538561 is about 1240.3874394720. The cubic root of 1538561 is about 115.4440550386. Note that the first 3 decimals are identical.

The spelling of 1538561 in words is "one million, five hundred thirty-eight thousand, five hundred sixty-one".