197811939 has 16 divisors (see below), whose sum is σ = 288280832. Its totient is φ = 119911968.

The previous prime is 197811919. The next prime is 197811941. The reversal of 197811939 is 939118791.

It is a happy number.

It is not a de Polignac number, because 197811939 - 2¹³ = 197803747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (197811919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35239 + ... + 40464.

It is an arithmetic number, because the mean of its divisors is an integer number (18017552).

Almost surely, 2^197811939 is an apocalyptic number.

197811939 is a deficient number, since it is larger than the sum of its proper divisors (90468893).

197811939 is a wasteful number, since it uses less digits than its factorization.

197811939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75786.

The product of its digits is 122472, while the sum is 48.

The square root of 197811939 is about 14064.5632353088. The cubic root of 197811939 is about 582.6630797113.

The spelling of 197811939 in words is "one hundred ninety-seven million, eight hundred eleven thousand, nine hundred thirty-nine".