16921494949 has 4 divisors (see below), whose sum is σ = 17334214380. Its totient is φ = 16508775520.

The previous prime is 16921494923. The next prime is 16921494971. The reversal of 16921494949 is 94949412961.

16921494949 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10202414049 + 6719080900 = 101007^2 + 81970^2 .

It is a cyclic number.

It is not a de Polignac number, because 16921494949 - 2²⁹ = 16384624037 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16921494893 and 16921494902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16921492949) 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, 206359654 + ... + 206359735.

It is an arithmetic number, because the mean of its divisors is an integer number (4333553595).

Almost surely, 2^16921494949 is an apocalyptic number.

It is an amenable number.

16921494949 is a deficient number, since it is larger than the sum of its proper divisors (412719431).

16921494949 is an equidigital number, since it uses as much as digits as its factorization.

16921494949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412719430.

The product of its digits is 5038848, while the sum is 58.

The spelling of 16921494949 in words is "sixteen billion, nine hundred twenty-one million, four hundred ninety-four thousand, nine hundred forty-nine".