16821712 has 20 divisors (see below), whose sum is σ = 32961060. Its totient is φ = 8315648.

The previous prime is 16821709. The next prime is 16821719. The reversal of 16821712 is 21712861.

It can be written as a sum of positive squares in 2 ways, for example, as 4822416 + 11999296 = 2196^2 + 3464^2 .

It is a super-2 number, since 2×16821712² = 565939989221888, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16821719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4483 + ... + 7330.

It is an arithmetic number, because the mean of its divisors is an integer number (1648053).

Almost surely, 2^16821712 is an apocalyptic number.

It is an amenable number.

16821712 is a deficient number, since it is larger than the sum of its proper divisors (16139348).

16821712 is a wasteful number, since it uses less digits than its factorization.

16821712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11910 (or 11904 counting only the distinct ones).

The product of its digits is 1344, while the sum is 28.

The square root of 16821712 is about 4101.4280439866. The cubic root of 16821712 is about 256.2261185755.

The spelling of 16821712 in words is "sixteen million, eight hundred twenty-one thousand, seven hundred twelve".