97817987 has 2 divisors, whose sum is σ = 97817988. Its totient is φ = 97817986.

The previous prime is 97817981. The next prime is 97817999. The reversal of 97817987 is 78971879.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 97817987 - 2⁴ = 97817971 is a prime.

It is not a weakly prime, because it can be changed into another prime (97817981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48908993 + 48908994.

It is an arithmetic number, because the mean of its divisors is an integer number (48908994).

Almost surely, 2^97817987 is an apocalyptic number.

97817987 is a deficient number, since it is larger than the sum of its proper divisors (1).

97817987 is an equidigital number, since it uses as much as digits as its factorization.

97817987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1778112, while the sum is 56.

The square root of 97817987 is about 9890.2976193844. The cubic root of 97817987 is about 460.7580239697.

The spelling of 97817987 in words is "ninety-seven million, eight hundred seventeen thousand, nine hundred eighty-seven".