16601591 has 2 divisors, whose sum is σ = 16601592. Its totient is φ = 16601590.

The previous prime is 16601551. The next prime is 16601593. The reversal of 16601591 is 19510661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16601591 - 2¹⁰ = 16600567 is a prime.

It is a super-2 number, since 2×16601591² = 551225647462562, which contains 22 as substring.

Together with 16601593, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16601593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8300795 + 8300796.

It is an arithmetic number, because the mean of its divisors is an integer number (8300796).

Almost surely, 2^16601591 is an apocalyptic number.

16601591 is a deficient number, since it is larger than the sum of its proper divisors (1).

16601591 is an equidigital number, since it uses as much as digits as its factorization.

16601591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 16601591 is about 4074.5050006105. The cubic root of 16601591 is about 255.1035898489.

The spelling of 16601591 in words is "sixteen million, six hundred one thousand, five hundred ninety-one".