1961009161 has 2 divisors, whose sum is σ = 1961009162. Its totient is φ = 1961009160.

The previous prime is 1961009123. The next prime is 1961009201. The reversal of 1961009161 is 1619001691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1462603536 + 498405625 = 38244^2 + 22325^2 .

It is a cyclic number.

It is not a de Polignac number, because 1961009161 - 2⁹ = 1961008649 is a prime.

It is not a weakly prime, because it can be changed into another prime (1961009111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 980504580 + 980504581.

It is an arithmetic number, because the mean of its divisors is an integer number (980504581).

Almost surely, 2^1961009161 is an apocalyptic number.

It is an amenable number.

1961009161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1961009161 is an equidigital number, since it uses as much as digits as its factorization.

1961009161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 1961009161 is about 44283.2830874135. The cubic root of 1961009161 is about 1251.6796962321.

The spelling of 1961009161 in words is "one billion, nine hundred sixty-one million, nine thousand, one hundred sixty-one".