16493821 has 2 divisors, whose sum is σ = 16493822. Its totient is φ = 16493820.

The previous prime is 16493801. The next prime is 16493831. The reversal of 16493821 is 12839461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8732025 + 7761796 = 2955^2 + 2786^2 .

It is a cyclic number.

It is not a de Polignac number, because 16493821 - 2¹¹ = 16491773 is a prime.

It is a super-2 number, since 2×16493821² = 544092262360082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16493801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8246910 + 8246911.

It is an arithmetic number, because the mean of its divisors is an integer number (8246911).

Almost surely, 2^16493821 is an apocalyptic number.

It is an amenable number.

16493821 is a deficient number, since it is larger than the sum of its proper divisors (1).

16493821 is an equidigital number, since it uses as much as digits as its factorization.

16493821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 34.

The square root of 16493821 is about 4061.2585487752. The cubic root of 16493821 is about 254.5503854603.

The spelling of 16493821 in words is "sixteen million, four hundred ninety-three thousand, eight hundred twenty-one".