1561107869 has 4 divisors (see below), whose sum is σ = 1561455744. Its totient is φ = 1560759996.

The previous prime is 1561107853. The next prime is 1561107881. The reversal of 1561107869 is 9687011651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1561107869 - 2⁴ = 1561107853 is a prime.

It is a super-2 number, since 2×1561107869² = 4874115557307442322, 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 (1561100869) 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, 167117 + ... + 176210.

It is an arithmetic number, because the mean of its divisors is an integer number (390363936).

Almost surely, 2^1561107869 is an apocalyptic number.

It is an amenable number.

1561107869 is a deficient number, since it is larger than the sum of its proper divisors (347875).

1561107869 is an equidigital number, since it uses as much as digits as its factorization.

1561107869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347874.

The product of its (nonzero) digits is 90720, while the sum is 44.

The square root of 1561107869 is about 39510.8576090168. The cubic root of 1561107869 is about 1160.0524820191.

The spelling of 1561107869 in words is "one billion, five hundred sixty-one million, one hundred seven thousand, eight hundred sixty-nine".