989969971 has 2 divisors, whose sum is σ = 989969972. Its totient is φ = 989969970.

The previous prime is 989969963. The next prime is 989969989. The reversal of 989969971 is 179969989.

It is a weak prime.

It is an emirp because it is prime and its reverse (179969989) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 989969971 - 2³ = 989969963 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 989969897 and 989969906.

It is not a weakly prime, because it can be changed into another prime (989969171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494984985 + 494984986.

It is an arithmetic number, because the mean of its divisors is an integer number (494984986).

Almost surely, 2^989969971 is an apocalyptic number.

989969971 is a deficient number, since it is larger than the sum of its proper divisors (1).

989969971 is an equidigital number, since it uses as much as digits as its factorization.

989969971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19840464, while the sum is 67.

The square root of 989969971 is about 31463.7882493510. The cubic root of 989969971 is about 996.6454163518.

The spelling of 989969971 in words is "nine hundred eighty-nine million, nine hundred sixty-nine thousand, nine hundred seventy-one".