197387681 has 2 divisors, whose sum is σ = 197387682. Its totient is φ = 197387680.

The previous prime is 197387677. The next prime is 197387699. The reversal of 197387681 is 186783791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 154157056 + 43230625 = 12416^2 + 6575^2 .

It is a cyclic number.

It is not a de Polignac number, because 197387681 - 2² = 197387677 is a prime.

It is a super-2 number, since 2×197387681² = 77923793221115522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (197387651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98693840 + 98693841.

It is an arithmetic number, because the mean of its divisors is an integer number (98693841).

Almost surely, 2^197387681 is an apocalyptic number.

It is an amenable number.

197387681 is a deficient number, since it is larger than the sum of its proper divisors (1).

197387681 is an equidigital number, since it uses as much as digits as its factorization.

197387681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 50.

The square root of 197387681 is about 14049.4726235542. The cubic root of 197387681 is about 582.2462251771.

The spelling of 197387681 in words is "one hundred ninety-seven million, three hundred eighty-seven thousand, six hundred eighty-one".