105991961 has 2 divisors, whose sum is σ = 105991962. Its totient is φ = 105991960.

The previous prime is 105991931. The next prime is 105991979. The reversal of 105991961 is 169199501.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67551961 + 38440000 = 8219^2 + 6200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-105991961 is a prime.

It is a super-2 number, since 2×105991961² = 22468591593251042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (105991931) 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, 52995980 + 52995981.

It is an arithmetic number, because the mean of its divisors is an integer number (52995981).

Almost surely, 2^105991961 is an apocalyptic number.

It is an amenable number.

105991961 is a deficient number, since it is larger than the sum of its proper divisors (1).

105991961 is an equidigital number, since it uses as much as digits as its factorization.

105991961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21870, while the sum is 41.

The square root of 105991961 is about 10295.2397252322. The cubic root of 105991961 is about 473.2503848012.

The spelling of 105991961 in words is "one hundred five million, nine hundred ninety-one thousand, nine hundred sixty-one".