16988521 has 6 divisors (see below), whose sum is σ = 18673466. Its totient is φ = 15444000.

The previous prime is 16988509. The next prime is 16988549. The reversal of 16988521 is 12588961.

It can be written as a sum of positive squares in only one way, i.e., 9486400 + 7502121 = 3080^2 + 2739^2 .

It is not a de Polignac number, because 16988521 - 2⁷ = 16988393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16988501) 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 5 ways as a sum of consecutive naturals, for example, 70080 + ... + 70321.

Almost surely, 2^16988521 is an apocalyptic number.

16988521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16988521 is a deficient number, since it is larger than the sum of its proper divisors (1684945).

16988521 is a wasteful number, since it uses less digits than its factorization.

16988521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140423 (or 140412 counting only the distinct ones).

The product of its digits is 34560, while the sum is 40.

The square root of 16988521 is about 4121.7133573309. The cubic root of 16988521 is about 257.0702720320.

The spelling of 16988521 in words is "sixteen million, nine hundred eighty-eight thousand, five hundred twenty-one".