1561601306 has 4 divisors (see below), whose sum is σ = 2342401962. Its totient is φ = 780800652.

The previous prime is 1561601297. The next prime is 1561601329. The reversal of 1561601306 is 6031061651.

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

It can be written as a sum of positive squares in only one way, i.e., 1537345681 + 24255625 = 39209^2 + 4925^2 .

It is a Curzon number.

It is an unprimeable number.

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, 390400325 + ... + 390400328.

Almost surely, 2^1561601306 is an apocalyptic number.

1561601306 is a deficient number, since it is larger than the sum of its proper divisors (780800656).

1561601306 is an equidigital number, since it uses as much as digits as its factorization.

1561601306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 780800655.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 1561601306 is about 39517.1014372259. The cubic root of 1561601306 is about 1160.1746927749.

Adding to 1561601306 its reverse (6031061651), we get a palindrome (7592662957).

The spelling of 1561601306 in words is "one billion, five hundred sixty-one million, six hundred one thousand, three hundred six".