161115645961 has 2 divisors, whose sum is σ = 161115645962. Its totient is φ = 161115645960.

The previous prime is 161115645923. The next prime is 161115646033. The reversal of 161115645961 is 169546511161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 110535635961 + 50580010000 = 332469^2 + 224900^2 .

It is a cyclic number.

It is not a de Polignac number, because 161115645961 - 2³³ = 152525711369 is a prime.

It is a super-2 number, since 2×161115645961² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161115645461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80557822980 + 80557822981.

It is an arithmetic number, because the mean of its divisors is an integer number (80557822981).

Almost surely, 2^161115645961 is an apocalyptic number.

It is an amenable number.

161115645961 is a deficient number, since it is larger than the sum of its proper divisors (1).

161115645961 is an equidigital number, since it uses as much as digits as its factorization.

161115645961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 194400, while the sum is 46.

The spelling of 161115645961 in words is "one hundred sixty-one billion, one hundred fifteen million, six hundred forty-five thousand, nine hundred sixty-one".