16821797 has 4 divisors (see below), whose sum is σ = 16842240. Its totient is φ = 16801356.

The previous prime is 16821793. The next prime is 16821839. The reversal of 16821797 is 79712861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79712861 = 73 ⋅1091957.

It is a cyclic number.

It is not a de Polignac number, because 16821797 - 2² = 16821793 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 (16821793) 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, 8933 + ... + 10650.

It is an arithmetic number, because the mean of its divisors is an integer number (4210560).

Almost surely, 2^16821797 is an apocalyptic number.

It is an amenable number.

16821797 is a deficient number, since it is larger than the sum of its proper divisors (20443).

16821797 is an equidigital number, since it uses as much as digits as its factorization.

16821797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20442.

The product of its digits is 42336, while the sum is 41.

The square root of 16821797 is about 4101.4384062180. The cubic root of 16821797 is about 256.2265501444.

The spelling of 16821797 in words is "sixteen million, eight hundred twenty-one thousand, seven hundred ninety-seven".