161561027 has 2 divisors, whose sum is σ = 161561028. Its totient is φ = 161561026.

The previous prime is 161561017. The next prime is 161561051. The reversal of 161561027 is 720165161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161561027 - 2⁴ = 161561011 is a prime.

It is a super-2 number, since 2×161561027² = 52203930890589458, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161561017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80780513 + 80780514.

It is an arithmetic number, because the mean of its divisors is an integer number (80780514).

Almost surely, 2^161561027 is an apocalyptic number.

161561027 is a deficient number, since it is larger than the sum of its proper divisors (1).

161561027 is an equidigital number, since it uses as much as digits as its factorization.

161561027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 161561027 is about 12710.6658755551. The cubic root of 161561027 is about 544.6433454753.

The spelling of 161561027 in words is "one hundred sixty-one million, five hundred sixty-one thousand, twenty-seven".