161224309 has 2 divisors, whose sum is σ = 161224310. Its totient is φ = 161224308.

The previous prime is 161224307. The next prime is 161224337. The reversal of 161224309 is 903422161.

161224309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (161224337) can be obtained adding 161224309 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 94148209 + 67076100 = 9703^2 + 8190^2 .

It is a cyclic number.

It is not a de Polignac number, because 161224309 - 2¹ = 161224307 is a prime.

Together with 161224307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161224307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80612154 + 80612155.

It is an arithmetic number, because the mean of its divisors is an integer number (80612155).

Almost surely, 2^161224309 is an apocalyptic number.

It is an amenable number.

161224309 is a deficient number, since it is larger than the sum of its proper divisors (1).

161224309 is an equidigital number, since it uses as much as digits as its factorization.

161224309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 161224309 is about 12697.4134767676. The cubic root of 161224309 is about 544.2647088401.

It can be divided in two parts, 1612 and 24309, that added together give a square (25921 = 161²).

The spelling of 161224309 in words is "one hundred sixty-one million, two hundred twenty-four thousand, three hundred nine".