5781621913 has 2 divisors, whose sum is σ = 5781621914. Its totient is φ = 5781621912.

The previous prime is 5781621863. The next prime is 5781621947. The reversal of 5781621913 is 3191261875.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3434897664 + 2346724249 = 58608^2 + 48443^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5781621913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 5781621913.

It is not a weakly prime, because it can be changed into another prime (5781628913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2890810956 + 2890810957.

It is an arithmetic number, because the mean of its divisors is an integer number (2890810957).

Almost surely, 2^5781621913 is an apocalyptic number.

It is an amenable number.

5781621913 is a deficient number, since it is larger than the sum of its proper divisors (1).

5781621913 is an equidigital number, since it uses as much as digits as its factorization.

5781621913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 5781621913 is about 76036.9772742184. The cubic root of 5781621913 is about 1794.8020734425.

The spelling of 5781621913 in words is "five billion, seven hundred eighty-one million, six hundred twenty-one thousand, nine hundred thirteen".