16688690 has 8 divisors (see below), whose sum is σ = 30039660. Its totient is φ = 6675472.

The previous prime is 16688677. The next prime is 16688701. The reversal of 16688690 is 9688661.

It can be written as a sum of positive squares in 2 ways, for example, as 16459249 + 229441 = 4057^2 + 479^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×16688690² = 557024747832200, which contains 22 as substring.

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 834425 + ... + 834444.

Almost surely, 2^16688690 is an apocalyptic number.

16688690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16688690 is a deficient number, since it is larger than the sum of its proper divisors (13350970).

16688690 is a wasteful number, since it uses less digits than its factorization.

16688690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1668876.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 16688690 is about 4085.1793106301. The cubic root of 16688690 is about 255.5489391972.

The spelling of 16688690 in words is "sixteen million, six hundred eighty-eight thousand, six hundred ninety".