197981969 has 2 divisors, whose sum is σ = 197981970. Its totient is φ = 197981968.

The previous prime is 197981941. The next prime is 197982011. The reversal of 197981969 is 969189791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191545600 + 6436369 = 13840^2 + 2537^2 .

It is a cyclic number.

It is not a de Polignac number, because 197981969 - 2⁸ = 197981713 is a prime.

It is a super-2 number, since 2×197981969² = 78393720098233922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (197983969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98990984 + 98990985.

It is an arithmetic number, because the mean of its divisors is an integer number (98990985).

Almost surely, 2^197981969 is an apocalyptic number.

It is an amenable number.

197981969 is a deficient number, since it is larger than the sum of its proper divisors (1).

197981969 is an equidigital number, since it uses as much as digits as its factorization.

197981969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2204496, while the sum is 59.

The square root of 197981969 is about 14070.6065611970. The cubic root of 197981969 is about 582.8299753195.

The spelling of 197981969 in words is "one hundred ninety-seven million, nine hundred eighty-one thousand, nine hundred sixty-nine".