161521963 has 2 divisors, whose sum is σ = 161521964. Its totient is φ = 161521962.

The previous prime is 161521949. The next prime is 161521979. The reversal of 161521963 is 369125161.

It is a weak prime.

It is an emirp because it is prime and its reverse (369125161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161521963 - 2⁵ = 161521931 is a prime.

It is not a weakly prime, because it can be changed into another prime (161521163) 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, 80760981 + 80760982.

It is an arithmetic number, because the mean of its divisors is an integer number (80760982).

Almost surely, 2^161521963 is an apocalyptic number.

161521963 is a deficient number, since it is larger than the sum of its proper divisors (1).

161521963 is an equidigital number, since it uses as much as digits as its factorization.

161521963 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 34.

The square root of 161521963 is about 12709.1291204394. The cubic root of 161521963 is about 544.5994453197.

The spelling of 161521963 in words is "one hundred sixty-one million, five hundred twenty-one thousand, nine hundred sixty-three".