16821793 has 2 divisors, whose sum is σ = 16821794. Its totient is φ = 16821792.

The previous prime is 16821781. The next prime is 16821839. The reversal of 16821793 is 39712861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13046544 + 3775249 = 3612^2 + 1943^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16821793 is a prime.

It is not a weakly prime, because it can be changed into another prime (16821703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8410896 + 8410897.

It is an arithmetic number, because the mean of its divisors is an integer number (8410897).

Almost surely, 2^16821793 is an apocalyptic number.

It is an amenable number.

16821793 is a deficient number, since it is larger than the sum of its proper divisors (1).

16821793 is an equidigital number, since it uses as much as digits as its factorization.

16821793 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 37.

The square root of 16821793 is about 4101.4379185842. The cubic root of 16821793 is about 256.2265298353.

The spelling of 16821793 in words is "sixteen million, eight hundred twenty-one thousand, seven hundred ninety-three".