197974921 has 2 divisors, whose sum is σ = 197974922. Its totient is φ = 197974920.

The previous prime is 197974879. The next prime is 197974949. The reversal of 197974921 is 129479791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159037321 + 38937600 = 12611^2 + 6240^2 .

It is a cyclic number.

It is not a de Polignac number, because 197974921 - 2¹⁹ = 197450633 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (197974991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98987460 + 98987461.

It is an arithmetic number, because the mean of its divisors is an integer number (98987461).

Almost surely, 2^197974921 is an apocalyptic number.

It is an amenable number.

197974921 is a deficient number, since it is larger than the sum of its proper divisors (1).

197974921 is an equidigital number, since it uses as much as digits as its factorization.

197974921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 49.

The square root of 197974921 is about 14070.3561077892. The cubic root of 197974921 is about 582.8230591436.

The spelling of 197974921 in words is "one hundred ninety-seven million, nine hundred seventy-four thousand, nine hundred twenty-one".