1561361 has 4 divisors (see below), whose sum is σ = 1583424. Its totient is φ = 1539300.

The previous prime is 1561349. The next prime is 1561367. The reversal of 1561361 is 1631651.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561361 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10925 + ... + 11066.

It is an arithmetic number, because the mean of its divisors is an integer number (395856).

2^1561361 is an apocalyptic number.

It is an amenable number.

1561361 is a deficient number, since it is larger than the sum of its proper divisors (22063).

1561361 is an equidigital number, since it uses as much as digits as its factorization.

1561361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22062.

The product of its digits is 540, while the sum is 23.

The square root of 1561361 is about 1249.5443169412. The cubic root of 1561361 is about 116.0115178813.

The spelling of 1561361 in words is "one million, five hundred sixty-one thousand, three hundred sixty-one".