19864626449 has 2 divisors, whose sum is σ = 19864626450. Its totient is φ = 19864626448.

The previous prime is 19864626433. The next prime is 19864626461. The reversal of 19864626449 is 94462646891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16846222849 + 3018403600 = 129793^2 + 54940^2 .

It is a cyclic number.

It is not a de Polignac number, because 19864626449 - 2⁴ = 19864626433 is a prime.

It is not a weakly prime, because it can be changed into another prime (19864626479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9932313224 + 9932313225.

It is an arithmetic number, because the mean of its divisors is an integer number (9932313225).

Almost surely, 2^19864626449 is an apocalyptic number.

It is an amenable number.

19864626449 is a deficient number, since it is larger than the sum of its proper divisors (1).

19864626449 is an equidigital number, since it uses as much as digits as its factorization.

19864626449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17915904, while the sum is 59.

It can be divided in two parts, 19 and 864626449, that added together give a palindrome (864626468).

The spelling of 19864626449 in words is "nineteen billion, eight hundred sixty-four million, six hundred twenty-six thousand, four hundred forty-nine".