161616491 has 2 divisors, whose sum is σ = 161616492. Its totient is φ = 161616490.

The previous prime is 161616487. The next prime is 161616577. The reversal of 161616491 is 194616161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161616491 - 2² = 161616487 is a prime.

It is a super-2 number, since 2×161616491² = 52239780326306162, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161612491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80808245 + 80808246.

It is an arithmetic number, because the mean of its divisors is an integer number (80808246).

Almost surely, 2^161616491 is an apocalyptic number.

161616491 is a deficient number, since it is larger than the sum of its proper divisors (1).

161616491 is an equidigital number, since it uses as much as digits as its factorization.

161616491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 35.

The square root of 161616491 is about 12712.8474780436. The cubic root of 161616491 is about 544.7056638097.

The spelling of 161616491 in words is "one hundred sixty-one million, six hundred sixteen thousand, four hundred ninety-one".