97890809 has 2 divisors, whose sum is σ = 97890810. Its totient is φ = 97890808.

The previous prime is 97890797. The next prime is 97890817. The reversal of 97890809 is 90809879.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65934400 + 31956409 = 8120^2 + 5653^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-97890809 is a prime.

It is a super-2 number, since 2×97890809² = 19165220973348962, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (97890209) 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, 48945404 + 48945405.

It is an arithmetic number, because the mean of its divisors is an integer number (48945405).

Almost surely, 2^97890809 is an apocalyptic number.

It is an amenable number.

97890809 is a deficient number, since it is larger than the sum of its proper divisors (1).

97890809 is an equidigital number, since it uses as much as digits as its factorization.

97890809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 326592, while the sum is 50.

The square root of 97890809 is about 9893.9784212419. The cubic root of 97890809 is about 460.8723349088.

The spelling of 97890809 in words is "ninety-seven million, eight hundred ninety thousand, eight hundred nine".