197720881 has 2 divisors, whose sum is σ = 197720882. Its totient is φ = 197720880.

The previous prime is 197720879. The next prime is 197720891. The reversal of 197720881 is 188027791.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158533281 + 39187600 = 12591^2 + 6260^2 .

It is a cyclic number.

It is not a de Polignac number, because 197720881 - 2¹ = 197720879 is a prime.

It is a super-2 number, since 2×197720881² = 78187093566832322, which contains 22 as substring.

Together with 197720879, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (197720851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98860440 + 98860441.

It is an arithmetic number, because the mean of its divisors is an integer number (98860441).

Almost surely, 2^197720881 is an apocalyptic number.

It is an amenable number.

197720881 is a deficient number, since it is larger than the sum of its proper divisors (1).

197720881 is an equidigital number, since it uses as much as digits as its factorization.

197720881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56448, while the sum is 43.

The square root of 197720881 is about 14061.3257198601. The cubic root of 197720881 is about 582.5736609801.

The spelling of 197720881 in words is "one hundred ninety-seven million, seven hundred twenty thousand, eight hundred eighty-one".