97871561 has 2 divisors, whose sum is σ = 97871562. Its totient is φ = 97871560.

The previous prime is 97871539. The next prime is 97871563. The reversal of 97871561 is 16517879.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69622336 + 28249225 = 8344^2 + 5315^2 .

It is a cyclic number.

It is not a de Polignac number, because 97871561 - 2¹⁸ = 97609417 is a prime.

Together with 97871563, 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 (97871563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48935780 + 48935781.

It is an arithmetic number, because the mean of its divisors is an integer number (48935781).

Almost surely, 2^97871561 is an apocalyptic number.

It is an amenable number.

97871561 is a deficient number, since it is larger than the sum of its proper divisors (1).

97871561 is an equidigital number, since it uses as much as digits as its factorization.

97871561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 105840, while the sum is 44.

The square root of 97871561 is about 9893.0056605665. The cubic root of 97871561 is about 460.8421262430.

The spelling of 97871561 in words is "ninety-seven million, eight hundred seventy-one thousand, five hundred sixty-one".