19544420857 has 8 divisors (see below), whose sum is σ = 21147593600. Its totient is φ = 17955498960.

The previous prime is 19544420839. The next prime is 19544420869. The reversal of 19544420857 is 75802444591.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19544420857 is a prime.

It is a super-2 number, since 2×19544420857² (a number of 21 digits) contains 22 as substring.

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 19544420857.

It is not an unprimeable number, because it can be changed into a prime (19544420837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3559857 + ... + 3565342.

It is an arithmetic number, because the mean of its divisors is an integer number (2643449200).

Almost surely, 2^19544420857 is an apocalyptic number.

It is an amenable number.

19544420857 is a deficient number, since it is larger than the sum of its proper divisors (1603172743).

19544420857 is a wasteful number, since it uses less digits than its factorization.

19544420857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7125423.

The product of its (nonzero) digits is 1612800, while the sum is 49.

The spelling of 19544420857 in words is "nineteen billion, five hundred forty-four million, four hundred twenty thousand, eight hundred fifty-seven".