16989551 has 4 divisors (see below), whose sum is σ = 16998504. Its totient is φ = 16980600.

The previous prime is 16989547. The next prime is 16989569. The reversal of 16989551 is 15598961.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 15598961 = 7 ⋅2228423.

It is a cyclic number.

It is not a de Polignac number, because 16989551 - 2² = 16989547 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 (16289551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 380 + ... + 5841.

It is an arithmetic number, because the mean of its divisors is an integer number (4249626).

Almost surely, 2^16989551 is an apocalyptic number.

16989551 is a deficient number, since it is larger than the sum of its proper divisors (8953).

16989551 is an equidigital number, since it uses as much as digits as its factorization.

16989551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8952.

The product of its digits is 97200, while the sum is 44.

The square root of 16989551 is about 4121.8383034758. The cubic root of 16989551 is about 257.0754672465.

The spelling of 16989551 in words is "sixteen million, nine hundred eighty-nine thousand, five hundred fifty-one".