19554408649 has 2 divisors, whose sum is σ = 19554408650. Its totient is φ = 19554408648.

The previous prime is 19554408583. The next prime is 19554408659. The reversal of 19554408649 is 94680445591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17202158649 + 2352250000 = 131157^2 + 48500^2 .

It is a cyclic number.

It is not a de Polignac number, because 19554408649 - 2¹¹ = 19554406601 is a prime.

It is a super-2 number, since 2×19554408649² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19554408649.

It is not a weakly prime, because it can be changed into another prime (19554408659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9777204324 + 9777204325.

It is an arithmetic number, because the mean of its divisors is an integer number (9777204325).

Almost surely, 2^19554408649 is an apocalyptic number.

It is an amenable number.

19554408649 is a deficient number, since it is larger than the sum of its proper divisors (1).

19554408649 is an equidigital number, since it uses as much as digits as its factorization.

19554408649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6220800, while the sum is 55.

The spelling of 19554408649 in words is "nineteen billion, five hundred fifty-four million, four hundred eight thousand, six hundred forty-nine".