19236399421 has 4 divisors (see below), whose sum is σ = 19253113344. Its totient is φ = 19219685500.

The previous prime is 19236399407. The next prime is 19236399431. The reversal of 19236399421 is 12499363291.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19236399421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19236399431) 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 3 ways as a sum of consecutive naturals, for example, 8355235 + ... + 8357536.

It is an arithmetic number, because the mean of its divisors is an integer number (4813278336).

Almost surely, 2^19236399421 is an apocalyptic number.

It is an amenable number.

19236399421 is a deficient number, since it is larger than the sum of its proper divisors (16713923).

19236399421 is a wasteful number, since it uses less digits than its factorization.

19236399421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16713922.

The product of its digits is 629856, while the sum is 49.

The spelling of 19236399421 in words is "nineteen billion, two hundred thirty-six million, three hundred ninety-nine thousand, four hundred twenty-one".