989977 has 2 divisors, whose sum is σ = 989978. Its totient is φ = 989976.

The previous prime is 989971. The next prime is 989981. The reversal of 989977 is 779989.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 549081 + 440896 = 741^2 + 664^2 .

It is a cyclic number.

It is not a de Polignac number, because 989977 - 2¹¹ = 987929 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 989977.

It is not a weakly prime, because it can be changed into another prime (989971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494988 + 494989.

It is an arithmetic number, because the mean of its divisors is an integer number (494989).

2⁹⁸⁹⁹⁷⁷ is an apocalyptic number.

It is an amenable number.

989977 is a deficient number, since it is larger than the sum of its proper divisors (1).

989977 is an equidigital number, since it uses as much as digits as its factorization.

989977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 49.

The square root of 989977 is about 994.9758791046. The cubic root of 989977 is about 99.6647775145.

The spelling of 989977 in words is "nine hundred eighty-nine thousand, nine hundred seventy-seven".