97978987 has 2 divisors, whose sum is σ = 97978988. Its totient is φ = 97978986.

The previous prime is 97978981. The next prime is 97979009. The reversal of 97978987 is 78987979.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-97978987 is a prime.

It is not a weakly prime, because it can be changed into another prime (97978981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48989493 + 48989494.

It is an arithmetic number, because the mean of its divisors is an integer number (48989494).

Almost surely, 2^97978987 is an apocalyptic number.

97978987 is a deficient number, since it is larger than the sum of its proper divisors (1).

97978987 is an equidigital number, since it uses as much as digits as its factorization.

97978987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16003008, while the sum is 64.

The square root of 97978987 is about 9898.4335629432. The cubic root of 97978987 is about 461.0106747763.

The spelling of 97978987 in words is "ninety-seven million, nine hundred seventy-eight thousand, nine hundred eighty-seven".