172197340981 has 2 divisors, whose sum is σ = 172197340982. Its totient is φ = 172197340980.

The previous prime is 172197340979. The next prime is 172197341021. The reversal of 172197340981 is 189043791271.

It is a happy number.

172197340981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111378382756 + 60818958225 = 333734^2 + 246615^2 .

It is an emirp because it is prime and its reverse (189043791271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172197340981 - 2¹ = 172197340979 is a prime.

It is a super-2 number, since 2×172197340981² (a number of 23 digits) contains 22 as substring.

Together with 172197340979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172197340681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86098670490 + 86098670491.

It is an arithmetic number, because the mean of its divisors is an integer number (86098670491).

Almost surely, 2^172197340981 is an apocalyptic number.

It is an amenable number.

172197340981 is a deficient number, since it is larger than the sum of its proper divisors (1).

172197340981 is an equidigital number, since it uses as much as digits as its factorization.

172197340981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 762048, while the sum is 52.

The spelling of 172197340981 in words is "one hundred seventy-two billion, one hundred ninety-seven million, three hundred forty thousand, nine hundred eighty-one".