19561938481 has 2 divisors, whose sum is σ = 19561938482. Its totient is φ = 19561938480.

The previous prime is 19561938467. The next prime is 19561938503. The reversal of 19561938481 is 18483916591.

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., 10736275456 + 8825663025 = 103616^2 + 93945^2 .

It is a cyclic number.

It is not a de Polignac number, because 19561938481 - 2⁷ = 19561938353 is a prime.

It is a super-2 number, since 2×19561938481² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19561936481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9780969240 + 9780969241.

It is an arithmetic number, because the mean of its divisors is an integer number (9780969241).

Almost surely, 2^19561938481 is an apocalyptic number.

It is an amenable number.

19561938481 is a deficient number, since it is larger than the sum of its proper divisors (1).

19561938481 is an equidigital number, since it uses as much as digits as its factorization.

19561938481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1866240, while the sum is 55.

The spelling of 19561938481 in words is "nineteen billion, five hundred sixty-one million, nine hundred thirty-eight thousand, four hundred eighty-one".