161572068781 has 2 divisors, whose sum is σ = 161572068782. Its totient is φ = 161572068780.

The previous prime is 161572068761. The next prime is 161572068787. The reversal of 161572068781 is 187860275161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122076866025 + 39495202756 = 349395^2 + 198734^2 .

It is a cyclic number.

It is not a de Polignac number, because 161572068781 - 2¹³ = 161572060589 is a prime.

It is a super-2 number, since 2×161572068781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161572068787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80786034390 + 80786034391.

It is an arithmetic number, because the mean of its divisors is an integer number (80786034391).

Almost surely, 2^161572068781 is an apocalyptic number.

It is an amenable number.

161572068781 is a deficient number, since it is larger than the sum of its proper divisors (1).

161572068781 is an equidigital number, since it uses as much as digits as its factorization.

161572068781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1128960, while the sum is 52.

The spelling of 161572068781 in words is "one hundred sixty-one billion, five hundred seventy-two million, sixty-eight thousand, seven hundred eighty-one".