1261616089 has 2 divisors, whose sum is σ = 1261616090. Its totient is φ = 1261616088.

The previous prime is 1261616077. The next prime is 1261616107. The reversal of 1261616089 is 9806161621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 780252489 + 481363600 = 27933^2 + 21940^2 .

It is an emirp because it is prime and its reverse (9806161621) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261616089 is a prime.

It is not a weakly prime, because it can be changed into another prime (1261616009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630808044 + 630808045.

It is an arithmetic number, because the mean of its divisors is an integer number (630808045).

Almost surely, 2^1261616089 is an apocalyptic number.

It is an amenable number.

1261616089 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261616089 is an equidigital number, since it uses as much as digits as its factorization.

1261616089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 1261616089 is about 35519.2354788219. The cubic root of 1261616089 is about 1080.5438758699.

The spelling of 1261616089 in words is "one billion, two hundred sixty-one million, six hundred sixteen thousand, eighty-nine".