19429644120649 has 9 divisors (see below), whose sum is σ = 22601866808871. Its totient is φ = 16653954227400.

The previous prime is 19429644120611. The next prime is 19429644120703. The reversal of 19429644120649 is 94602144692491.

The square root of 19429644120649 is 4407907.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 15833690430649 + 3595953690000 = 3979157^2 + 1896300^2 .

It is not a de Polignac number, because 19429644120649 - 2¹¹ = 19429644118601 is a prime.

It is a super-2 number, since 2×19429644120649² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19429644123649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 30540499 + ... + 31170199.

It is an arithmetic number, because the mean of its divisors is an integer number (2511318534319).

Almost surely, 2^{19429644120649} is an apocalyptic number.

19429644120649 is the 4407907-th square number.

19429644120649 is the 2203954-th centered octagonal number.

It is an amenable number.

19429644120649 is a deficient number, since it is larger than the sum of its proper divisors (3172222688222).

19429644120649 is an frugal number, since it uses more digits than its factorization.

19429644120649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1259416 (or 629708 counting only the distinct ones).

The product of its (nonzero) digits is 26873856, while the sum is 61.

The spelling of 19429644120649 in words is "nineteen trillion, four hundred twenty-nine billion, six hundred forty-four million, one hundred twenty thousand, six hundred forty-nine".