197981919 has 24 divisors (see below), whose sum is σ = 302914560. Its totient is φ = 124256592.

The previous prime is 197981897. The next prime is 197981921. The reversal of 197981919 is 919189791.

It is a happy number.

It is not a de Polignac number, because 197981919 - 2⁵ = 197981887 is a prime.

It is a super-2 number, since 2×197981919² = 78393680501845122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197981969) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24322 + ... + 31424.

It is an arithmetic number, because the mean of its divisors is an integer number (12621440).

Almost surely, 2^197981919 is an apocalyptic number.

197981919 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

197981919 is a deficient number, since it is larger than the sum of its proper divisors (104932641).

197981919 is a wasteful number, since it uses less digits than its factorization.

197981919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7291 (or 7288 counting only the distinct ones).

The product of its digits is 367416, while the sum is 54.

The square root of 197981919 is about 14070.6047844433. The cubic root of 197981919 is about 582.8299262553.

The spelling of 197981919 in words is "one hundred ninety-seven million, nine hundred eighty-one thousand, nine hundred nineteen".