161245549 has 2 divisors, whose sum is σ = 161245550. Its totient is φ = 161245548.

The previous prime is 161245547. The next prime is 161245559. The reversal of 161245549 is 945542161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82355625 + 78889924 = 9075^2 + 8882^2 .

It is an emirp because it is prime and its reverse (945542161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161245549 - 2¹ = 161245547 is a prime.

It is a super-2 number, since 2×161245549² = 52000254144622802, which contains 22 as substring.

Together with 161245547, 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 (161245547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80622774 + 80622775.

It is an arithmetic number, because the mean of its divisors is an integer number (80622775).

Almost surely, 2^161245549 is an apocalyptic number.

It is an amenable number.

161245549 is a deficient number, since it is larger than the sum of its proper divisors (1).

161245549 is an equidigital number, since it uses as much as digits as its factorization.

161245549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 37.

The square root of 161245549 is about 12698.2498400370. The cubic root of 161245549 is about 544.2886086165.

The spelling of 161245549 in words is "one hundred sixty-one million, two hundred forty-five thousand, five hundred forty-nine".