16721293 has 2 divisors, whose sum is σ = 16721294. Its totient is φ = 16721292.

The previous prime is 16721291. The next prime is 16721297. The reversal of 16721293 is 39212761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15824484 + 896809 = 3978^2 + 947^2 .

It is a cyclic number.

It is not a de Polignac number, because 16721293 - 2¹ = 16721291 is a prime.

Together with 16721291, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16721291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8360646 + 8360647.

It is an arithmetic number, because the mean of its divisors is an integer number (8360647).

Almost surely, 2^16721293 is an apocalyptic number.

It is an amenable number.

16721293 is a deficient number, since it is larger than the sum of its proper divisors (1).

16721293 is an equidigital number, since it uses as much as digits as its factorization.

16721293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4536, while the sum is 31.

The square root of 16721293 is about 4089.1677637387. The cubic root of 16721293 is about 255.7152442891.

The spelling of 16721293 in words is "sixteen million, seven hundred twenty-one thousand, two hundred ninety-three".