19897331 has 2 divisors, whose sum is σ = 19897332. Its totient is φ = 19897330.

The previous prime is 19897301. The next prime is 19897333. The reversal of 19897331 is 13379891.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19897331 is a prime.

It is a super-2 number, since 2×19897331² = 791807561847122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 19897333, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19897333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9948665 + 9948666.

It is an arithmetic number, because the mean of its divisors is an integer number (9948666).

Almost surely, 2^19897331 is an apocalyptic number.

19897331 is a deficient number, since it is larger than the sum of its proper divisors (1).

19897331 is an equidigital number, since it uses as much as digits as its factorization.

19897331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 41.

The square root of 19897331 is about 4460.6424425188. The cubic root of 19897331 is about 270.9764870238.

The spelling of 19897331 in words is "nineteen million, eight hundred ninety-seven thousand, three hundred thirty-one".