19489021 has 4 divisors (see below), whose sum is σ = 20635452. Its totient is φ = 18342592.

The previous prime is 19489009. The next prime is 19489031. The reversal of 19489021 is 12098491.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12098491 = 2383 ⋅5077.

It can be written as a sum of positive squares in 2 ways, for example, as 15444900 + 4044121 = 3930^2 + 2011^2 .

It is not a de Polignac number, because 19489021 - 2¹³ = 19480829 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 (19489031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 573190 + ... + 573223.

It is an arithmetic number, because the mean of its divisors is an integer number (5158863).

Almost surely, 2^19489021 is an apocalyptic number.

It is an amenable number.

19489021 is a deficient number, since it is larger than the sum of its proper divisors (1146431).

19489021 is a wasteful number, since it uses less digits than its factorization.

19489021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1146430.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 19489021 is about 4414.6371311808. The cubic root of 19489021 is about 269.1101063422.

The spelling of 19489021 in words is "nineteen million, four hundred eighty-nine thousand, twenty-one".