67775191961 has 2 divisors, whose sum is σ = 67775191962. Its totient is φ = 67775191960.

The previous prime is 67775191919. The next prime is 67775191969. The reversal of 67775191961 is 16919157776.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50106136336 + 17669055625 = 223844^2 + 132925^2 .

It is a cyclic number.

It is not a de Polignac number, because 67775191961 - 2¹⁰ = 67775190937 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 67775191961.

It is not a weakly prime, because it can be changed into another prime (67775191969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33887595980 + 33887595981.

It is an arithmetic number, because the mean of its divisors is an integer number (33887595981).

Almost surely, 2^67775191961 is an apocalyptic number.

It is an amenable number.

67775191961 is a deficient number, since it is larger than the sum of its proper divisors (1).

67775191961 is an equidigital number, since it uses as much as digits as its factorization.

67775191961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5000940, while the sum is 59.

The spelling of 67775191961 in words is "sixty-seven billion, seven hundred seventy-five million, one hundred ninety-one thousand, nine hundred sixty-one".