16421393 has 4 divisors (see below), whose sum is σ = 16580928. Its totient is φ = 16261860.

The previous prime is 16421387. The next prime is 16421417. The reversal of 16421393 is 39312461.

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, and also an emirpimes, since its reverse is a distinct semiprime: 39312461 = 773 ⋅50857.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16421393 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (16421323) 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, 79613 + ... + 79818.

It is an arithmetic number, because the mean of its divisors is an integer number (4145232).

Almost surely, 2^16421393 is an apocalyptic number.

It is an amenable number.

16421393 is a deficient number, since it is larger than the sum of its proper divisors (159535).

16421393 is a wasteful number, since it uses less digits than its factorization.

16421393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159534.

The product of its digits is 3888, while the sum is 29.

The square root of 16421393 is about 4052.3317978665. The cubic root of 16421393 is about 254.1772431443.

The spelling of 16421393 in words is "sixteen million, four hundred twenty-one thousand, three hundred ninety-three".