1561965089 has 2 divisors, whose sum is σ = 1561965090. Its totient is φ = 1561965088.

The previous prime is 1561965077. The next prime is 1561965107. The reversal of 1561965089 is 9805691651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1561830400 + 134689 = 39520^2 + 367^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561965089 - 2¹² = 1561960993 is a prime.

It is not a weakly prime, because it can be changed into another prime (1561965289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780982544 + 780982545.

It is an arithmetic number, because the mean of its divisors is an integer number (780982545).

Almost surely, 2^1561965089 is an apocalyptic number.

It is an amenable number.

1561965089 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561965089 is an equidigital number, since it uses as much as digits as its factorization.

1561965089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 583200, while the sum is 50.

The square root of 1561965089 is about 39521.7040244977. The cubic root of 1561965089 is about 1160.2647753202.

It can be divided in two parts, 15619 and 65089, that added together give a palindrome (80708).

The spelling of 1561965089 in words is "one billion, five hundred sixty-one million, nine hundred sixty-five thousand, eighty-nine".