1561204343 has 4 divisors (see below), whose sum is σ = 1570553040. Its totient is φ = 1551855648.

The previous prime is 1561204301. The next prime is 1561204349. The reversal of 1561204343 is 3434021651.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1561204343 - 2⁶ = 1561204279 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 (1561204349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4674098 + ... + 4674431.

It is an arithmetic number, because the mean of its divisors is an integer number (392638260).

Almost surely, 2^1561204343 is an apocalyptic number.

1561204343 is a deficient number, since it is larger than the sum of its proper divisors (9348697).

1561204343 is an equidigital number, since it uses as much as digits as its factorization.

1561204343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9348696.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 1561204343 is about 39512.0784444453. The cubic root of 1561204343 is about 1160.0763779971.

Adding to 1561204343 its reverse (3434021651), we get a palindrome (4995225994).

The spelling of 1561204343 in words is "one billion, five hundred sixty-one million, two hundred four thousand, three hundred forty-three".