16991594909 has 2 divisors, whose sum is σ = 16991594910. Its totient is φ = 16991594908.

The previous prime is 16991594903. The next prime is 16991594951. The reversal of 16991594909 is 90949519961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13659765625 + 3331829284 = 116875^2 + 57722^2 .

It is a cyclic number.

It is not a de Polignac number, because 16991594909 - 2¹² = 16991590813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16991594903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8495797454 + 8495797455.

It is an arithmetic number, because the mean of its divisors is an integer number (8495797455).

Almost surely, 2^16991594909 is an apocalyptic number.

It is an amenable number.

16991594909 is a deficient number, since it is larger than the sum of its proper divisors (1).

16991594909 is an equidigital number, since it uses as much as digits as its factorization.

16991594909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7085880, while the sum is 62.

The spelling of 16991594909 in words is "sixteen billion, nine hundred ninety-one million, five hundred ninety-four thousand, nine hundred nine".