16389991 has 2 divisors, whose sum is σ = 16389992. Its totient is φ = 16389990.

The previous prime is 16389983. The next prime is 16390013. The reversal of 16389991 is 19998361.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16389991 - 2³ = 16389983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16389941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8194995 + 8194996.

It is an arithmetic number, because the mean of its divisors is an integer number (8194996).

Almost surely, 2^16389991 is an apocalyptic number.

16389991 is a deficient number, since it is larger than the sum of its proper divisors (1).

16389991 is an equidigital number, since it uses as much as digits as its factorization.

16389991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104976, while the sum is 46.

The square root of 16389991 is about 4048.4553844645. The cubic root of 16389991 is about 254.0151219633.

The spelling of 16389991 in words is "sixteen million, three hundred eighty-nine thousand, nine hundred ninety-one".