19810097 has 2 divisors, whose sum is σ = 19810098. Its totient is φ = 19810096.

The previous prime is 19810081. The next prime is 19810111. The reversal of 19810097 is 79001891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19722481 + 87616 = 4441^2 + 296^2 .

It is an emirp because it is prime and its reverse (79001891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19810097 - 2⁴ = 19810081 is a prime.

It is a super-3 number, since 3×19810097³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19810397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9905048 + 9905049.

It is an arithmetic number, because the mean of its divisors is an integer number (9905049).

Almost surely, 2^19810097 is an apocalyptic number.

It is an amenable number.

19810097 is a deficient number, since it is larger than the sum of its proper divisors (1).

19810097 is an equidigital number, since it uses as much as digits as its factorization.

19810097 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 19810097 is about 4450.8535136533. The cubic root of 19810097 is about 270.5799012973.

The spelling of 19810097 in words is "nineteen million, eight hundred ten thousand, ninety-seven".