16606921 has 2 divisors, whose sum is σ = 16606922. Its totient is φ = 16606920.

The previous prime is 16606871. The next prime is 16606939. The reversal of 16606921 is 12960661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16605625 + 1296 = 4075^2 + 36^2 .

It is a cyclic number.

It is not a de Polignac number, because 16606921 - 2¹⁵ = 16574153 is a prime.

It is not a weakly prime, because it can be changed into another prime (16606951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8303460 + 8303461.

It is an arithmetic number, because the mean of its divisors is an integer number (8303461).

Almost surely, 2^16606921 is an apocalyptic number.

It is an amenable number.

16606921 is a deficient number, since it is larger than the sum of its proper divisors (1).

16606921 is an equidigital number, since it uses as much as digits as its factorization.

16606921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 16606921 is about 4075.1590153023. The cubic root of 16606921 is about 255.1308875669.

The spelling of 16606921 in words is "sixteen million, six hundred six thousand, nine hundred twenty-one".