172197341021 has 2 divisors, whose sum is σ = 172197341022. Its totient is φ = 172197341020.

The previous prime is 172197340981. The next prime is 172197341023. The reversal of 172197341021 is 120143791271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91046424121 + 81150916900 = 301739^2 + 284870^2 .

It is a cyclic number.

It is not a de Polignac number, because 172197341021 - 2¹⁸ = 172197078877 is a prime.

Together with 172197341023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172197341023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86098670510 + 86098670511.

It is an arithmetic number, because the mean of its divisors is an integer number (86098670511).

Almost surely, 2^172197341021 is an apocalyptic number.

It is an amenable number.

172197341021 is a deficient number, since it is larger than the sum of its proper divisors (1).

172197341021 is an equidigital number, since it uses as much as digits as its factorization.

172197341021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21168, while the sum is 38.

The spelling of 172197341021 in words is "one hundred seventy-two billion, one hundred ninety-seven million, three hundred forty-one thousand, twenty-one".