19621917449 has 8 divisors (see below), whose sum is σ = 20414373888. Its totient is φ = 18839429280.

The previous prime is 19621917437. The next prime is 19621917451. The reversal of 19621917449 is 94471912691.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19621917449 - 2⁴ = 19621917433 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19621917449.

It is not an unprimeable number, because it can be changed into a prime (19621917149) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2488052 + ... + 2495925.

It is an arithmetic number, because the mean of its divisors is an integer number (2551796736).

Almost surely, 2^19621917449 is an apocalyptic number.

It is an amenable number.

19621917449 is a deficient number, since it is larger than the sum of its proper divisors (792456439).

19621917449 is a wasteful number, since it uses less digits than its factorization.

19621917449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4984135.

The product of its digits is 979776, while the sum is 53.

The spelling of 19621917449 in words is "nineteen billion, six hundred twenty-one million, nine hundred seventeen thousand, four hundred forty-nine".