1561944359 has 2 divisors, whose sum is σ = 1561944360. Its totient is φ = 1561944358.

The previous prime is 1561944337. The next prime is 1561944443. The reversal of 1561944359 is 9534491651.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561944359 - 2¹⁶ = 1561878823 is a prime.

It is a super-2 number, since 2×1561944359² = 4879340361223841762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561914359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780972179 + 780972180.

It is an arithmetic number, because the mean of its divisors is an integer number (780972180).

Almost surely, 2^1561944359 is an apocalyptic number.

1561944359 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561944359 is an equidigital number, since it uses as much as digits as its factorization.

1561944359 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 583200, while the sum is 47.

The square root of 1561944359 is about 39521.4417626685. The cubic root of 1561944359 is about 1160.2596423854.

The spelling of 1561944359 in words is "one billion, five hundred sixty-one million, nine hundred forty-four thousand, three hundred fifty-nine".