1561361047 has 4 divisors (see below), whose sum is σ = 1562695576. Its totient is φ = 1560026520.

The previous prime is 1561361033. The next prime is 1561361059. The reversal of 1561361047 is 7401631651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7401631651 = 18233 ⋅405947.

It is a cyclic number.

It is not a de Polignac number, because 1561361047 - 2²³ = 1552972439 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 (1561361027) 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, 665508 + ... + 667849.

It is an arithmetic number, because the mean of its divisors is an integer number (390673894).

Almost surely, 2^1561361047 is an apocalyptic number.

1561361047 is a deficient number, since it is larger than the sum of its proper divisors (1334529).

1561361047 is a wasteful number, since it uses less digits than its factorization.

1561361047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1334528.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 1561361047 is about 39514.0613832595. The cubic root of 1561361047 is about 1160.1151904536.

Adding to 1561361047 its reverse (7401631651), we get a palindrome (8962992698).

The spelling of 1561361047 in words is "one billion, five hundred sixty-one million, three hundred sixty-one thousand, forty-seven".