16662989 has 6 divisors (see below), whose sum is σ = 19383534. Its totient is φ = 14282520.

The previous prime is 16662979. The next prime is 16662991. The reversal of 16662989 is 98926661.

It can be written as a sum of positive squares in only one way, i.e., 16540489 + 122500 = 4067^2 + 350^2 .

It is not a de Polignac number, because 16662989 - 2¹² = 16658893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16662949) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 169982 + ... + 170079.

It is an arithmetic number, because the mean of its divisors is an integer number (3230589).

Almost surely, 2^16662989 is an apocalyptic number.

It is an amenable number.

16662989 is a deficient number, since it is larger than the sum of its proper divisors (2720545).

16662989 is an equidigital number, since it uses as much as digits as its factorization.

16662989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340075 (or 340068 counting only the distinct ones).

The product of its digits is 279936, while the sum is 47.

The square root of 16662989 is about 4082.0324594496. The cubic root of 16662989 is about 255.4176878780.

The spelling of 16662989 in words is "sixteen million, six hundred sixty-two thousand, nine hundred eighty-nine".