16993989 has 16 divisors (see below), whose sum is σ = 25858240. Its totient is φ = 11022480.

The previous prime is 16993969. The next prime is 16994009. The reversal of 16993989 is 98939961.

It is an interprime number because it is at equal distance from previous prime (16993969) and next prime (16994009).

It is not a de Polignac number, because 16993989 - 2⁹ = 16993477 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 (16993919) 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 in 15 ways as a sum of consecutive naturals, for example, 7507 + ... + 9504.

It is an arithmetic number, because the mean of its divisors is an integer number (1616140).

Almost surely, 2^16993989 is an apocalyptic number.

It is an amenable number.

16993989 is a deficient number, since it is larger than the sum of its proper divisors (8864251).

16993989 is a wasteful number, since it uses less digits than its factorization.

16993989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17057 (or 17051 counting only the distinct ones).

The product of its digits is 944784, while the sum is 54.

The square root of 16993989 is about 4122.3766203490. The cubic root of 16993989 is about 257.0978496625.

The spelling of 16993989 in words is "sixteen million, nine hundred ninety-three thousand, nine hundred eighty-nine".