19904281 has 2 divisors, whose sum is σ = 19904282. Its totient is φ = 19904280.

The previous prime is 19904279. The next prime is 19904317. The reversal of 19904281 is 18240991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19501056 + 403225 = 4416^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 19904281 - 2¹ = 19904279 is a prime.

It is a super-2 number, since 2×19904281² = 792360804253922, which contains 22 as substring.

Together with 19904279, it forms a pair of twin primes.

It is a zygodrome in base 7.

It is not a weakly prime, because it can be changed into another prime (19904221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9952140 + 9952141.

It is an arithmetic number, because the mean of its divisors is an integer number (9952141).

Almost surely, 2^19904281 is an apocalyptic number.

It is an amenable number.

19904281 is a deficient number, since it is larger than the sum of its proper divisors (1).

19904281 is an equidigital number, since it uses as much as digits as its factorization.

19904281 is an odious number, because the sum of its binary digits is odd.

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

The square root of 19904281 is about 4461.4214102683. The cubic root of 19904281 is about 271.0080334215.

The spelling of 19904281 in words is "nineteen million, nine hundred four thousand, two hundred eighty-one".