100191961 has 2 divisors, whose sum is σ = 100191962. Its totient is φ = 100191960.

The previous prime is 100191943. The next prime is 100191977. The reversal of 100191961 is 169191001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 99102025 + 1089936 = 9955^2 + 1044^2 .

It is a cyclic number.

It is not a de Polignac number, because 100191961 - 2²¹ = 98094809 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (100191941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50095980 + 50095981.

It is an arithmetic number, because the mean of its divisors is an integer number (50095981).

Almost surely, 2^100191961 is an apocalyptic number.

It is an amenable number.

100191961 is a deficient number, since it is larger than the sum of its proper divisors (1).

100191961 is an equidigital number, since it uses as much as digits as its factorization.

100191961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 486, while the sum is 28.

The square root of 100191961 is about 10009.5934482875. The cubic root of 100191961 is about 464.4556948661.

The spelling of 100191961 in words is "one hundred million, one hundred ninety-one thousand, nine hundred sixty-one".