19609823581 has 2 divisors, whose sum is σ = 19609823582. Its totient is φ = 19609823580.

The previous prime is 19609823579. The next prime is 19609823591. The reversal of 19609823581 is 18532890691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19413963556 + 195860025 = 139334^2 + 13995^2 .

It is a cyclic number.

It is not a de Polignac number, because 19609823581 - 2¹ = 19609823579 is a prime.

It is a super-2 number, since 2×19609823581² (a number of 21 digits) contains 22 as substring.

Together with 19609823579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19609823551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9804911790 + 9804911791.

It is an arithmetic number, because the mean of its divisors is an integer number (9804911791).

Almost surely, 2^19609823581 is an apocalyptic number.

It is an amenable number.

19609823581 is a deficient number, since it is larger than the sum of its proper divisors (1).

19609823581 is an equidigital number, since it uses as much as digits as its factorization.

19609823581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 933120, while the sum is 52.

The spelling of 19609823581 in words is "nineteen billion, six hundred nine million, eight hundred twenty-three thousand, five hundred eighty-one".