9778999 has 2 divisors, whose sum is σ = 9779000. Its totient is φ = 9778998.

The previous prime is 9778997. The next prime is 9779027. The reversal of 9778999 is 9998779.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9778999 - 2¹ = 9778997 is a prime.

It is a super-4 number, since 4×9778999⁴ (a number of 29 digits) contains 4444 as substring.

Together with 9778997, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9778991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4889499 + 4889500.

It is an arithmetic number, because the mean of its divisors is an integer number (4889500).

Almost surely, 2^9778999 is an apocalyptic number.

9778999 is a deficient number, since it is larger than the sum of its proper divisors (1).

9778999 is an equidigital number, since it uses as much as digits as its factorization.

9778999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2571912, while the sum is 58.

The square root of 9778999 is about 3127.1391078748. The cubic root of 9778999 is about 213.8445241568.

The spelling of 9778999 in words is "nine million, seven hundred seventy-eight thousand, nine hundred ninety-nine".