16988391 has 24 divisors (see below), whose sum is σ = 28732704. Its totient is φ = 9469440.

The previous prime is 16988381. The next prime is 16988393. The reversal of 16988391 is 19388961.

It is not a de Polignac number, because 16988391 - 2¹⁸ = 16726247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16988393) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 706 + ... + 5871.

It is an arithmetic number, because the mean of its divisors is an integer number (1197196).

Almost surely, 2^16988391 is an apocalyptic number.

16988391 is a deficient number, since it is larger than the sum of its proper divisors (11744313).

16988391 is a wasteful number, since it uses less digits than its factorization.

16988391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6631 (or 6628 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 16988391 is about 4121.6975871599. The cubic root of 16988391 is about 257.0696163104.

The spelling of 16988391 in words is "sixteen million, nine hundred eighty-eight thousand, three hundred ninety-one".