19897061 has 2 divisors, whose sum is σ = 19897062. Its totient is φ = 19897060.

The previous prime is 19897049. The next prime is 19897063. The reversal of 19897061 is 16079891.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16248961 + 3648100 = 4031^2 + 1910^2 .

It is a cyclic number.

It is not a de Polignac number, because 19897061 - 2⁶ = 19896997 is a prime.

It is a Sophie Germain prime.

Together with 19897063, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19897063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9948530 + 9948531.

It is an arithmetic number, because the mean of its divisors is an integer number (9948531).

Almost surely, 2^19897061 is an apocalyptic number.

It is an amenable number.

19897061 is a deficient number, since it is larger than the sum of its proper divisors (1).

19897061 is an equidigital number, since it uses as much as digits as its factorization.

19897061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 41.

The square root of 19897061 is about 4460.6121777173. The cubic root of 19897061 is about 270.9752613320.

The spelling of 19897061 in words is "nineteen million, eight hundred ninety-seven thousand, sixty-one".