19930421 has 4 divisors (see below), whose sum is σ = 22777632. Its totient is φ = 17083212.

The previous prime is 19930399. The next prime is 19930429. The reversal of 19930421 is 12403991.

It is a happy number.

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 not a de Polignac number, because 19930421 - 2¹⁰ = 19929397 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 (19930429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1423595 + ... + 1423608.

It is an arithmetic number, because the mean of its divisors is an integer number (5694408).

Almost surely, 2^19930421 is an apocalyptic number.

It is an amenable number.

19930421 is a deficient number, since it is larger than the sum of its proper divisors (2847211).

19930421 is an equidigital number, since it uses as much as digits as its factorization.

19930421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2847210.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 19930421 is about 4464.3500086799. The cubic root of 19930421 is about 271.1266184818.

The spelling of 19930421 in words is "nineteen million, nine hundred thirty thousand, four hundred twenty-one".