197981669 has 4 divisors (see below), whose sum is σ = 198044640. Its totient is φ = 197918700.

The previous prime is 197981647. The next prime is 197981671. The reversal of 197981669 is 966189791.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 197981669 - 2¹⁶ = 197916133 is a prime.

It is a super-2 number, since 2×197981669² = 78393482520051122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197981689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26507 + ... + 33144.

It is an arithmetic number, because the mean of its divisors is an integer number (49511160).

Almost surely, 2^197981669 is an apocalyptic number.

It is an amenable number.

197981669 is a deficient number, since it is larger than the sum of its proper divisors (62971).

197981669 is an equidigital number, since it uses as much as digits as its factorization.

197981669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62970.

The product of its digits is 1469664, while the sum is 56.

The square root of 197981669 is about 14070.5959006717. The cubic root of 197981669 is about 582.8296809340.

The spelling of 197981669 in words is "one hundred ninety-seven million, nine hundred eighty-one thousand, six hundred sixty-nine".