161802257 has 2 divisors, whose sum is σ = 161802258. Its totient is φ = 161802256.

The previous prime is 161802239. The next prime is 161802287. The reversal of 161802257 is 752208161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85082176 + 76720081 = 9224^2 + 8759^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161802257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161802227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80901128 + 80901129.

It is an arithmetic number, because the mean of its divisors is an integer number (80901129).

Almost surely, 2^161802257 is an apocalyptic number.

It is an amenable number.

161802257 is a deficient number, since it is larger than the sum of its proper divisors (1).

161802257 is an equidigital number, since it uses as much as digits as its factorization.

161802257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 161802257 is about 12720.1516107317. The cubic root of 161802257 is about 544.9142832957.

The spelling of 161802257 in words is "one hundred sixty-one million, eight hundred two thousand, two hundred fifty-seven".