1561967669 has 2 divisors, whose sum is σ = 1561967670. Its totient is φ = 1561967668.

The previous prime is 1561967653. The next prime is 1561967681. The reversal of 1561967669 is 9667691651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1454430769 + 107536900 = 38137^2 + 10370^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561967669 - 2⁴ = 1561967653 is a prime.

It is a super-2 number, since 2×1561967669² = 4879485998002587122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561967609) 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 as a sum of consecutive naturals, namely, 780983834 + 780983835.

It is an arithmetic number, because the mean of its divisors is an integer number (780983835).

Almost surely, 2^1561967669 is an apocalyptic number.

It is an amenable number.

1561967669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561967669 is an equidigital number, since it uses as much as digits as its factorization.

1561967669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3674160, while the sum is 56.

The square root of 1561967669 is about 39521.7366647773. The cubic root of 1561967669 is about 1160.2654141483.

The spelling of 1561967669 in words is "one billion, five hundred sixty-one million, nine hundred sixty-seven thousand, six hundred sixty-nine".