1561043206 has 4 divisors (see below), whose sum is σ = 2341564812. Its totient is φ = 780521602.

The previous prime is 1561043203. The next prime is 1561043221. The reversal of 1561043206 is 6023401651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6023401651 = 593 ⋅10157507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561043203) 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 as a sum of consecutive naturals, namely, 390260800 + ... + 390260803.

It is an arithmetic number, because the mean of its divisors is an integer number (585391203).

Almost surely, 2^1561043206 is an apocalyptic number.

1561043206 is a deficient number, since it is larger than the sum of its proper divisors (780521606).

1561043206 is an equidigital number, since it uses as much as digits as its factorization.

1561043206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 780521605.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 1561043206 is about 39510.0393064851. The cubic root of 1561043206 is about 1160.0364648664.

Adding to 1561043206 its reverse (6023401651), we get a palindrome (7584444857).

The spelling of 1561043206 in words is "one billion, five hundred sixty-one million, forty-three thousand, two hundred six".