16921690609 has 2 divisors, whose sum is σ = 16921690610. Its totient is φ = 16921690608.

The previous prime is 16921690573. The next prime is 16921690619. The reversal of 16921690609 is 90609612961.

16921690609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16626813025 + 294877584 = 128945^2 + 17172^2 .

It is a cyclic number.

It is not a de Polignac number, because 16921690609 - 2⁷ = 16921690481 is a prime.

It is a super-2 number, since 2×16921690609² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16921690619) 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 as a sum of consecutive naturals, namely, 8460845304 + 8460845305.

It is an arithmetic number, because the mean of its divisors is an integer number (8460845305).

Almost surely, 2^16921690609 is an apocalyptic number.

It is an amenable number.

16921690609 is a deficient number, since it is larger than the sum of its proper divisors (1).

16921690609 is an equidigital number, since it uses as much as digits as its factorization.

16921690609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 314928, while the sum is 49.

The spelling of 16921690609 in words is "sixteen billion, nine hundred twenty-one million, six hundred ninety thousand, six hundred nine".