1561231 has 8 divisors (see below), whose sum is σ = 1793024. Its totient is φ = 1331640.

The previous prime is 1561213. The next prime is 1561243. The reversal of 1561231 is 1321651.

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 1561231 - 2¹¹ = 1559183 is a prime.

It is a super-2 number, since 2×1561231² = 4874884470722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1561199 and 1561208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1511231) 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 7 ways as a sum of consecutive naturals, for example, 1486 + ... + 2308.

It is an arithmetic number, because the mean of its divisors is an integer number (224128).

2^1561231 is an apocalyptic number.

1561231 is a deficient number, since it is larger than the sum of its proper divisors (231793).

1561231 is an equidigital number, since it uses as much as digits as its factorization.

1561231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101.

The product of its digits is 180, while the sum is 19.

The square root of 1561231 is about 1249.4922968950. The cubic root of 1561231 is about 116.0082980588.

Adding to 1561231 its reverse (1321651), we get a palindrome (2882882).

The spelling of 1561231 in words is "one million, five hundred sixty-one thousand, two hundred thirty-one".