989666989 has 8 divisors (see below), whose sum is σ = 1007783960. Its totient is φ = 971611200.

The previous prime is 989666969. The next prime is 989667031.

989666989 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 55875625 + 933791364 = 7475^2 + 30558^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 989666989 - 2⁵ = 989666957 is a prime.

It is a super-2 number, since 2×989666989² = 1958881498232652242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989666929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18007 + ... + 47995.

It is an arithmetic number, because the mean of its divisors is an integer number (125972995).

Almost surely, 2^989666989 is an apocalyptic number.

It is an amenable number.

989666989 is a deficient number, since it is larger than the sum of its proper divisors (18116971).

989666989 is a wasteful number, since it uses less digits than its factorization.

989666989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30591.

The product of its digits is 90699264, while the sum is 70.

The square root of 989666989 is about 31458.9731078432. The cubic root of 989666989 is about 996.5437309670.

The spelling of 989666989 in words is "nine hundred eighty-nine million, six hundred sixty-six thousand, nine hundred eighty-nine".