9726781613 has 2 divisors, whose sum is σ = 9726781614. Its totient is φ = 9726781612.

The previous prime is 9726781579. The next prime is 9726781621. The reversal of 9726781613 is 3161876279.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9452117284 + 274664329 = 97222^2 + 16573^2 .

It is a cyclic number.

It is not a de Polignac number, because 9726781613 - 2¹² = 9726777517 is a prime.

It is a super-2 number, since 2×9726781613² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9726781643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4863390806 + 4863390807.

It is an arithmetic number, because the mean of its divisors is an integer number (4863390807).

Almost surely, 2^9726781613 is an apocalyptic number.

It is an amenable number.

9726781613 is a deficient number, since it is larger than the sum of its proper divisors (1).

9726781613 is an equidigital number, since it uses as much as digits as its factorization.

9726781613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 50.

The square root of 9726781613 is about 98624.4473393894. The cubic root of 9726781613 is about 2134.6321939332.

The spelling of 9726781613 in words is "nine billion, seven hundred twenty-six million, seven hundred eighty-one thousand, six hundred thirteen".