161640529 has 2 divisors, whose sum is σ = 161640530. Its totient is φ = 161640528.

The previous prime is 161640503. The next prime is 161640587. The reversal of 161640529 is 925046161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158180929 + 3459600 = 12577^2 + 1860^2 .

It is a cyclic number.

It is not a de Polignac number, because 161640529 - 2⁵ = 161640497 is a prime.

It is a super-2 number, since 2×161640529² = 52255321230799682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161640494 and 161640503.

It is not a weakly prime, because it can be changed into another prime (161640599) 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, 80820264 + 80820265.

It is an arithmetic number, because the mean of its divisors is an integer number (80820265).

Almost surely, 2^161640529 is an apocalyptic number.

It is an amenable number.

161640529 is a deficient number, since it is larger than the sum of its proper divisors (1).

161640529 is an equidigital number, since it uses as much as digits as its factorization.

161640529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 161640529 is about 12713.7928644445. The cubic root of 161640529 is about 544.7326680376.

The spelling of 161640529 in words is "one hundred sixty-one million, six hundred forty thousand, five hundred twenty-nine".