16821065 has 16 divisors (see below), whose sum is σ = 21288960. Its totient is φ = 12740160.

The previous prime is 16821019. The next prime is 16821071. The reversal of 16821065 is 56012861.

It is a happy number.

It is not a de Polignac number, because 16821065 - 2⁶ = 16821001 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6131 + ... + 8439.

It is an arithmetic number, because the mean of its divisors is an integer number (1330560).

Almost surely, 2^16821065 is an apocalyptic number.

It is an amenable number.

16821065 is a deficient number, since it is larger than the sum of its proper divisors (4467895).

16821065 is a wasteful number, since it uses less digits than its factorization.

16821065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2392.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 16821065 is about 4101.3491682616. The cubic root of 16821065 is about 256.2228335269. Note that the first 3 decimals are identical.

The spelling of 16821065 in words is "sixteen million, eight hundred twenty-one thousand, sixty-five".