155691196961 has 2 divisors, whose sum is σ = 155691196962. Its totient is φ = 155691196960.

The previous prime is 155691196933. The next prime is 155691196963. The reversal of 155691196961 is 169691196551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153997380625 + 1693816336 = 392425^2 + 41156^2 .

It is a cyclic number.

It is not a de Polignac number, because 155691196961 - 2⁶ = 155691196897 is a prime.

It is a super-2 number, since 2×155691196961² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 155691196963, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 155691196961.

It is not a weakly prime, because it can be changed into another prime (155691196963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77845598480 + 77845598481.

It is an arithmetic number, because the mean of its divisors is an integer number (77845598481).

Almost surely, 2^155691196961 is an apocalyptic number.

It is an amenable number.

155691196961 is a deficient number, since it is larger than the sum of its proper divisors (1).

155691196961 is an equidigital number, since it uses as much as digits as its factorization.

155691196961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3936600, while the sum is 59.

The spelling of 155691196961 in words is "one hundred fifty-five billion, six hundred ninety-one million, one hundred ninety-six thousand, nine hundred sixty-one".