19021 has 4 divisors (see below), whose sum is σ = 19872. Its totient is φ = 18172.

The previous prime is 19013. The next prime is 19031. The reversal of 19021 is 12091.

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: 12091 = 107 ⋅113.

It is a cyclic number.

It is not a de Polignac number, because 19021 - 2³ = 19013 is a prime.

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 18992 and 19010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 391 + ... + 436.

It is an arithmetic number, because the mean of its divisors is an integer number (4968).

2¹⁹⁰²¹ is an apocalyptic number.

It is an amenable number.

19021 is a deficient number, since it is larger than the sum of its proper divisors (851).

19021 is an equidigital number, since it uses as much as digits as its factorization.

19021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 19021 is about 137.9166414904. The cubic root of 19021 is about 26.6938438210.

Multiplying 19021 by its product of nonzero digits (18), we get a triangular number (342378 = T₈₂₇).

The spelling of 19021 in words is "nineteen thousand, twenty-one".