197446318921 has 2 divisors, whose sum is σ = 197446318922. Its totient is φ = 197446318920.

The previous prime is 197446318913. The next prime is 197446318943. The reversal of 197446318921 is 129813644791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 152189713225 + 45256605696 = 390115^2 + 212736^2 .

It is a cyclic number.

It is not a de Polignac number, because 197446318921 - 2³ = 197446318913 is a prime.

It is not a weakly prime, because it can be changed into another prime (197446318981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98723159460 + 98723159461.

It is an arithmetic number, because the mean of its divisors is an integer number (98723159461).

Almost surely, 2^197446318921 is an apocalyptic number.

It is an amenable number.

197446318921 is a deficient number, since it is larger than the sum of its proper divisors (1).

197446318921 is an equidigital number, since it uses as much as digits as its factorization.

197446318921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2612736, while the sum is 55.

The spelling of 197446318921 in words is "one hundred ninety-seven billion, four hundred forty-six million, three hundred eighteen thousand, nine hundred twenty-one".