19802281 has 2 divisors, whose sum is σ = 19802282. Its totient is φ = 19802280.

The previous prime is 19802261. The next prime is 19802309. The reversal of 19802281 is 18220891.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12425625 + 7376656 = 3525^2 + 2716^2 .

It is a cyclic number.

It is not a de Polignac number, because 19802281 - 2¹¹ = 19800233 is a prime.

It is a super-2 number, since 2×19802281² = 784260665605922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19802261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9901140 + 9901141.

It is an arithmetic number, because the mean of its divisors is an integer number (9901141).

Almost surely, 2^19802281 is an apocalyptic number.

It is an amenable number.

19802281 is a deficient number, since it is larger than the sum of its proper divisors (1).

19802281 is an equidigital number, since it uses as much as digits as its factorization.

19802281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 19802281 is about 4449.9753931904. The cubic root of 19802281 is about 270.5443111854.

The spelling of 19802281 in words is "nineteen million, eight hundred two thousand, two hundred eighty-one".