163965961 has 2 divisors, whose sum is σ = 163965962. Its totient is φ = 163965960.

The previous prime is 163965947. The next prime is 163965979. The reversal of 163965961 is 169569361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154231561 + 9734400 = 12419^2 + 3120^2 .

It is a cyclic number.

It is not a de Polignac number, because 163965961 - 2¹⁹ = 163441673 is a prime.

It is not a weakly prime, because it can be changed into another prime (163965931) 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, 81982980 + 81982981.

It is an arithmetic number, because the mean of its divisors is an integer number (81982981).

Almost surely, 2^163965961 is an apocalyptic number.

It is an amenable number.

163965961 is a deficient number, since it is larger than the sum of its proper divisors (1).

163965961 is an equidigital number, since it uses as much as digits as its factorization.

163965961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 262440, while the sum is 46.

The square root of 163965961 is about 12804.9194062282. The cubic root of 163965961 is about 547.3324950629.

It can be divided in two parts, 1639 and 65961, that added together give a square (67600 = 260²).

The spelling of 163965961 in words is "one hundred sixty-three million, nine hundred sixty-five thousand, nine hundred sixty-one".