326181987161 has 2 divisors, whose sum is σ = 326181987162. Its totient is φ = 326181987160.

The previous prime is 326181987107. The next prime is 326181987191. The reversal of 326181987161 is 161789181623.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 239713056025 + 86468931136 = 489605^2 + 294056^2 .

It is an emirp because it is prime and its reverse (161789181623) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-326181987161 is a prime.

It is not a weakly prime, because it can be changed into another prime (326181987191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163090993580 + 163090993581.

It is an arithmetic number, because the mean of its divisors is an integer number (163090993581).

Almost surely, 2^326181987161 is an apocalyptic number.

It is an amenable number.

326181987161 is a deficient number, since it is larger than the sum of its proper divisors (1).

326181987161 is an equidigital number, since it uses as much as digits as its factorization.

326181987161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 53.

The spelling of 326181987161 in words is "three hundred twenty-six billion, one hundred eighty-one million, nine hundred eighty-seven thousand, one hundred sixty-one".