161536021 has 2 divisors, whose sum is σ = 161536022. Its totient is φ = 161536020.

The previous prime is 161535953. The next prime is 161536027. The reversal of 161536021 is 120635161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134235396 + 27300625 = 11586^2 + 5225^2 .

It is a cyclic number.

It is not a de Polignac number, because 161536021 - 2⁷ = 161535893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161536027) 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, 80768010 + 80768011.

It is an arithmetic number, because the mean of its divisors is an integer number (80768011).

Almost surely, 2^161536021 is an apocalyptic number.

It is an amenable number.

161536021 is a deficient number, since it is larger than the sum of its proper divisors (1).

161536021 is an equidigital number, since it uses as much as digits as its factorization.

161536021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 161536021 is about 12709.6821754126. The cubic root of 161536021 is about 544.6152445269.

It can be divided in two parts, 1615 and 36021, that added together give a square (37636 = 194²).

The spelling of 161536021 in words is "one hundred sixty-one million, five hundred thirty-six thousand, twenty-one".