16872521 has 2 divisors, whose sum is σ = 16872522. Its totient is φ = 16872520.

The previous prime is 16872473. The next prime is 16872523. The reversal of 16872521 is 12527861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15912121 + 960400 = 3989^2 + 980^2 .

It is a cyclic number.

It is not a de Polignac number, because 16872521 - 2¹⁴ = 16856137 is a prime.

Together with 16872523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16872523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8436260 + 8436261.

It is an arithmetic number, because the mean of its divisors is an integer number (8436261).

Almost surely, 2^16872521 is an apocalyptic number.

It is an amenable number.

16872521 is a deficient number, since it is larger than the sum of its proper divisors (1).

16872521 is an equidigital number, since it uses as much as digits as its factorization.

16872521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 32.

The square root of 16872521 is about 4107.6174359353. The cubic root of 16872521 is about 256.4838312964.

The spelling of 16872521 in words is "sixteen million, eight hundred seventy-two thousand, five hundred twenty-one".