997983887 has 2 divisors, whose sum is σ = 997983888. Its totient is φ = 997983886.

The previous prime is 997983841. The next prime is 997983901. The reversal of 997983887 is 788389799.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 997983887 - 2⁸ = 997983631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997989887) 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, 498991943 + 498991944.

It is an arithmetic number, because the mean of its divisors is an integer number (498991944).

Almost surely, 2^997983887 is an apocalyptic number.

997983887 is a deficient number, since it is larger than the sum of its proper divisors (1).

997983887 is an equidigital number, since it uses as much as digits as its factorization.

997983887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54867456, while the sum is 68.

The square root of 997983887 is about 31590.8829727819. The cubic root of 997983887 is about 999.3275101922.

The spelling of 997983887 in words is "nine hundred ninety-seven million, nine hundred eighty-three thousand, eight hundred eighty-seven".