16943921 has 2 divisors, whose sum is σ = 16943922. Its totient is φ = 16943920.

The previous prime is 16943881. The next prime is 16943929. The reversal of 16943921 is 12934961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15689521 + 1254400 = 3961^2 + 1120^2 .

It is a cyclic number.

It is not a de Polignac number, because 16943921 - 2²² = 12749617 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16943929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8471960 + 8471961.

It is an arithmetic number, because the mean of its divisors is an integer number (8471961).

Almost surely, 2^16943921 is an apocalyptic number.

It is an amenable number.

16943921 is a deficient number, since it is larger than the sum of its proper divisors (1).

16943921 is an equidigital number, since it uses as much as digits as its factorization.

16943921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 35.

The square root of 16943921 is about 4116.2994303136. The cubic root of 16943921 is about 256.8451125040.

The spelling of 16943921 in words is "sixteen million, nine hundred forty-three thousand, nine hundred twenty-one".