16728491 has 4 divisors (see below), whose sum is σ = 18015312. Its totient is φ = 15441672.

The previous prime is 16728479. The next prime is 16728583. The reversal of 16728491 is 19482761.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19482761 = 233 ⋅83617.

It is a cyclic number.

It is not a de Polignac number, because 16728491 - 2⁶ = 16728427 is a prime.

It is a super-2 number, since 2×16728491² = 559684822274162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16728421) 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, 643391 + ... + 643416.

It is an arithmetic number, because the mean of its divisors is an integer number (4503828).

Almost surely, 2^16728491 is an apocalyptic number.

16728491 is a deficient number, since it is larger than the sum of its proper divisors (1286821).

16728491 is a wasteful number, since it uses less digits than its factorization.

16728491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1286820.

The product of its digits is 24192, while the sum is 38.

The square root of 16728491 is about 4090.0477992317. The cubic root of 16728491 is about 255.7519315293.

The spelling of 16728491 in words is "sixteen million, seven hundred twenty-eight thousand, four hundred ninety-one".