161901108461 has 2 divisors, whose sum is σ = 161901108462. Its totient is φ = 161901108460.

The previous prime is 161901108437. The next prime is 161901108497. The reversal of 161901108461 is 164801109161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155546627236 + 6354481225 = 394394^2 + 79715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161901108461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161901108961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80950554230 + 80950554231.

It is an arithmetic number, because the mean of its divisors is an integer number (80950554231).

Almost surely, 2^161901108461 is an apocalyptic number.

It is an amenable number.

161901108461 is a deficient number, since it is larger than the sum of its proper divisors (1).

161901108461 is an equidigital number, since it uses as much as digits as its factorization.

161901108461 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 38.

The spelling of 161901108461 in words is "one hundred sixty-one billion, nine hundred one million, one hundred eight thousand, four hundred sixty-one".