16405643 has 2 divisors, whose sum is σ = 16405644. Its totient is φ = 16405642.

The previous prime is 16405639. The next prime is 16405657. The reversal of 16405643 is 34650461.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16405643 - 2² = 16405639 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (16405633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8202821 + 8202822.

It is an arithmetic number, because the mean of its divisors is an integer number (8202822).

Almost surely, 2^16405643 is an apocalyptic number.

16405643 is a deficient number, since it is larger than the sum of its proper divisors (1).

16405643 is an equidigital number, since it uses as much as digits as its factorization.

16405643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 16405643 is about 4050.3880061051. The cubic root of 16405643 is about 254.0959554376.

The spelling of 16405643 in words is "sixteen million, four hundred five thousand, six hundred forty-three".