19489921 has 8 divisors (see below), whose sum is σ = 21320064. Its totient is φ = 17669520.

The previous prime is 19489907. The next prime is 19489931. The reversal of 19489921 is 12998491.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19489921 - 2⁵ = 19489889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19489931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2136 + ... + 6598.

It is an arithmetic number, because the mean of its divisors is an integer number (2665008).

Almost surely, 2^19489921 is an apocalyptic number.

19489921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19489921 is a deficient number, since it is larger than the sum of its proper divisors (1830143).

19489921 is a wasteful number, since it uses less digits than its factorization.

19489921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4871.

The product of its digits is 46656, while the sum is 43.

The square root of 19489921 is about 4414.7390636367. The cubic root of 19489921 is about 269.1142487662.

The spelling of 19489921 in words is "nineteen million, four hundred eighty-nine thousand, nine hundred twenty-one".