16696821 has 4 divisors (see below), whose sum is σ = 22262432. Its totient is φ = 11131212.

The previous prime is 16696811. The next prime is 16696831. The reversal of 16696821 is 12869661.

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.

It is an interprime number because it is at equal distance from previous prime (16696811) and next prime (16696831).

It is not a de Polignac number, because 16696821 - 2⁵ = 16696789 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16696821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16696811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2782801 + ... + 2782806.

It is an arithmetic number, because the mean of its divisors is an integer number (5565608).

Almost surely, 2^16696821 is an apocalyptic number.

It is an amenable number.

16696821 is a deficient number, since it is larger than the sum of its proper divisors (5565611).

16696821 is an equidigital number, since it uses as much as digits as its factorization.

16696821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5565610.

The product of its digits is 31104, while the sum is 39.

The square root of 16696821 is about 4086.1743721971. The cubic root of 16696821 is about 255.5904349858.

The spelling of 16696821 in words is "sixteen million, six hundred ninety-six thousand, eight hundred twenty-one".