19921489 has 6 divisors (see below), whose sum is σ = 23174034. Its totient is φ = 17075520.

The previous prime is 19921483. The next prime is 19921523. The reversal of 19921489 is 98412991.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 13249600 + 6671889 = 3640^2 + 2583^2 .

It is not a de Polignac number, because 19921489 - 2⁵ = 19921457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19921483) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 203232 + ... + 203329.

It is an arithmetic number, because the mean of its divisors is an integer number (3862339).

Almost surely, 2^19921489 is an apocalyptic number.

It is an amenable number.

19921489 is a deficient number, since it is larger than the sum of its proper divisors (3252545).

19921489 is an equidigital number, since it uses as much as digits as its factorization.

19921489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406575 (or 406568 counting only the distinct ones).

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

The square root of 19921489 is about 4463.3495269808. The cubic root of 19921489 is about 271.0861098072.

It can be divided in two parts, 1992 and 1489, that added together give a square (3481 = 59²).

The spelling of 19921489 in words is "nineteen million, nine hundred twenty-one thousand, four hundred eighty-nine".