19668481 has 4 divisors (see below), whose sum is σ = 22478272. Its totient is φ = 16858692.

The previous prime is 19668457. The next prime is 19668487. The reversal of 19668481 is 18486691.

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.

It is a cyclic number.

It is not a de Polignac number, because 19668481 - 2⁵ = 19668449 is a prime.

It is a super-2 number, since 2×19668481² = 773698289694722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19668487) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1404885 + ... + 1404898.

It is an arithmetic number, because the mean of its divisors is an integer number (5619568).

Almost surely, 2^19668481 is an apocalyptic number.

19668481 is the 2561-st hex number.

It is an amenable number.

19668481 is a deficient number, since it is larger than the sum of its proper divisors (2809791).

19668481 is an equidigital number, since it uses as much as digits as its factorization.

19668481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2809790.

The product of its digits is 82944, while the sum is 43.

The square root of 19668481 is about 4434.9161209655. The cubic root of 19668481 is about 269.9335959241.

The spelling of 19668481 in words is "nineteen million, six hundred sixty-eight thousand, four hundred eighty-one".