19438505421 has 8 divisors (see below), whose sum is σ = 26016555840. Its totient is φ = 12909729312.

The previous prime is 19438505417. The next prime is 19438505423. The reversal of 19438505421 is 12450583491.

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

It is not a de Polignac number, because 19438505421 - 2² = 19438505417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19438505423) 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, 12317656 + ... + 12319233.

It is an arithmetic number, because the mean of its divisors is an integer number (3252069480).

Almost surely, 2^19438505421 is an apocalyptic number.

It is an amenable number.

19438505421 is a deficient number, since it is larger than the sum of its proper divisors (6578050419).

19438505421 is a wasteful number, since it uses less digits than its factorization.

19438505421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24637155.

The product of its (nonzero) digits is 172800, while the sum is 42.

The spelling of 19438505421 in words is "nineteen billion, four hundred thirty-eight million, five hundred five thousand, four hundred twenty-one".