16789991 has 2 divisors, whose sum is σ = 16789992. Its totient is φ = 16789990.

The previous prime is 16789979. The next prime is 16790017. The reversal of 16789991 is 19998761.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16789991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16789291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8394995 + 8394996.

It is an arithmetic number, because the mean of its divisors is an integer number (8394996).

Almost surely, 2^16789991 is an apocalyptic number.

16789991 is a deficient number, since it is larger than the sum of its proper divisors (1).

16789991 is an equidigital number, since it uses as much as digits as its factorization.

16789991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 50.

The square root of 16789991 is about 4097.5591514949. The cubic root of 16789991 is about 256.0649605248.

The spelling of 16789991 in words is "sixteen million, seven hundred eighty-nine thousand, nine hundred ninety-one".