1561061069 has 4 divisors (see below), whose sum is σ = 1566864540. Its totient is φ = 1555257600.

The previous prime is 1561061059. The next prime is 1561061077. The reversal of 1561061069 is 9601601651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9601601651 = 4157 ⋅2309743.

It can be written as a sum of positive squares in 2 ways, for example, as 54612100 + 1506448969 = 7390^2 + 38813^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561061069 - 2⁴ = 1561061053 is a prime.

It is a super-2 number, since 2×1561061069² = 4873823322294845522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561061009) 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, 2901332 + ... + 2901869.

It is an arithmetic number, because the mean of its divisors is an integer number (391716135).

Almost surely, 2^1561061069 is an apocalyptic number.

It is an amenable number.

1561061069 is a deficient number, since it is larger than the sum of its proper divisors (5803471).

1561061069 is an equidigital number, since it uses as much as digits as its factorization.

1561061069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5803470.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 1561061069 is about 39510.2653623081. The cubic root of 1561061069 is about 1160.0408896110.

The spelling of 1561061069 in words is "one billion, five hundred sixty-one million, sixty-one thousand, sixty-nine".