16971820321 has 4 divisors (see below), whose sum is σ = 16980049152. Its totient is φ = 16963591492.

The previous prime is 16971820291. The next prime is 16971820403. The reversal of 16971820321 is 12302817961.

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 a cyclic number.

It is not a de Polignac number, because 16971820321 - 2¹¹ = 16971818273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16971820121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4111321 + ... + 4115446.

It is an arithmetic number, because the mean of its divisors is an integer number (4245012288).

Almost surely, 2^16971820321 is an apocalyptic number.

It is an amenable number.

16971820321 is a deficient number, since it is larger than the sum of its proper divisors (8228831).

16971820321 is an equidigital number, since it uses as much as digits as its factorization.

16971820321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8228830.

The product of its (nonzero) digits is 36288, while the sum is 40.

The spelling of 16971820321 in words is "sixteen billion, nine hundred seventy-one million, eight hundred twenty thousand, three hundred twenty-one".