197921 has 2 divisors, whose sum is σ = 197922. Its totient is φ = 197920.

The previous prime is 197909. The next prime is 197927. The reversal of 197921 is 129791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130321 + 67600 = 361^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 197921 - 2¹⁴ = 181537 is a prime.

It is a plaindrome in base 11.

It is a nialpdrome in base 12.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 197921.

It is not a weakly prime, because it can be changed into another prime (197927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98960 + 98961.

It is an arithmetic number, because the mean of its divisors is an integer number (98961).

2¹⁹⁷⁹²¹ is an apocalyptic number.

It is an amenable number.

197921 is a deficient number, since it is larger than the sum of its proper divisors (1).

197921 is an equidigital number, since it uses as much as digits as its factorization.

197921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1134, while the sum is 29.

The square root of 197921 is about 444.8831307209. The cubic root of 197921 is about 58.2770141236.

The spelling of 197921 in words is "one hundred ninety-seven thousand, nine hundred twenty-one".