997989287 has 2 divisors, whose sum is σ = 997989288. Its totient is φ = 997989286.

The previous prime is 997989283. The next prime is 997989313. The reversal of 997989287 is 782989799.

It is a weak prime.

It is an emirp because it is prime and its reverse (782989799) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 997989287 - 2² = 997989283 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997989283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498994643 + 498994644.

It is an arithmetic number, because the mean of its divisors is an integer number (498994644).

Almost surely, 2^997989287 is an apocalyptic number.

997989287 is a deficient number, since it is larger than the sum of its proper divisors (1).

997989287 is an equidigital number, since it uses as much as digits as its factorization.

997989287 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41150592, while the sum is 68.

The square root of 997989287 is about 31590.9684403628. The cubic root of 997989287 is about 999.3293126123.

The spelling of 997989287 in words is "nine hundred ninety-seven million, nine hundred eighty-nine thousand, two hundred eighty-seven".