197831521 has 2 divisors, whose sum is σ = 197831522. Its totient is φ = 197831520.

The previous prime is 197831483. The next prime is 197831527. The reversal of 197831521 is 125138791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 185504400 + 12327121 = 13620^2 + 3511^2 .

It is a cyclic number.

It is not a de Polignac number, because 197831521 - 2⁷ = 197831393 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (197831527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98915760 + 98915761.

It is an arithmetic number, because the mean of its divisors is an integer number (98915761).

Almost surely, 2^197831521 is an apocalyptic number.

It is an amenable number.

197831521 is a deficient number, since it is larger than the sum of its proper divisors (1).

197831521 is an equidigital number, since it uses as much as digits as its factorization.

197831521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 37.

The square root of 197831521 is about 14065.2593648322. The cubic root of 197831521 is about 582.6823056017.

The spelling of 197831521 in words is "one hundred ninety-seven million, eight hundred thirty-one thousand, five hundred twenty-one".