16439993 has 2 divisors, whose sum is σ = 16439994. Its totient is φ = 16439992.

The previous prime is 16439971. The next prime is 16439999. The reversal of 16439993 is 39993461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15578809 + 861184 = 3947^2 + 928^2 .

It is a cyclic number.

It is not a de Polignac number, because 16439993 - 2¹⁴ = 16423609 is a prime.

It is not a weakly prime, because it can be changed into another prime (16439999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8219996 + 8219997.

It is an arithmetic number, because the mean of its divisors is an integer number (8219997).

Almost surely, 2^16439993 is an apocalyptic number.

It is an amenable number.

16439993 is a deficient number, since it is larger than the sum of its proper divisors (1).

16439993 is an equidigital number, since it uses as much as digits as its factorization.

16439993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 157464, while the sum is 44.

The square root of 16439993 is about 4054.6261233312. The cubic root of 16439993 is about 254.2731731480.

The spelling of 16439993 in words is "sixteen million, four hundred thirty-nine thousand, nine hundred ninety-three".