1911561089 has 2 divisors, whose sum is σ = 1911561090. Its totient is φ = 1911561088.

The previous prime is 1911561083. The next prime is 1911561143. The reversal of 1911561089 is 9801651191.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1183910464 + 727650625 = 34408^2 + 26975^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1911561089 is a prime.

It is not a weakly prime, because it can be changed into another prime (1911561083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 955780544 + 955780545.

It is an arithmetic number, because the mean of its divisors is an integer number (955780545).

Almost surely, 2^1911561089 is an apocalyptic number.

It is an amenable number.

1911561089 is a deficient number, since it is larger than the sum of its proper divisors (1).

1911561089 is an equidigital number, since it uses as much as digits as its factorization.

1911561089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 41.

The square root of 1911561089 is about 43721.4030996262. The cubic root of 1911561089 is about 1241.0693794848.

The spelling of 1911561089 in words is "one billion, nine hundred eleven million, five hundred sixty-one thousand, eighty-nine".