19980397 has 2 divisors, whose sum is σ = 19980398. Its totient is φ = 19980396.

The previous prime is 19980379. The next prime is 19980403. The reversal of 19980397 is 79308991.

Together with previous prime (19980379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18826921 + 1153476 = 4339^2 + 1074^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19980397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19980347) 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, 9990198 + 9990199.

It is an arithmetic number, because the mean of its divisors is an integer number (9990199).

Almost surely, 2^19980397 is an apocalyptic number.

It is an amenable number.

19980397 is a deficient number, since it is larger than the sum of its proper divisors (1).

19980397 is an equidigital number, since it uses as much as digits as its factorization.

19980397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 19980397 is about 4469.9437356638. The cubic root of 19980397 is about 271.3530481214.

The spelling of 19980397 in words is "nineteen million, nine hundred eighty thousand, three hundred ninety-seven".