197218939 has 4 divisors (see below), whose sum is σ = 197480224. Its totient is φ = 196957656.

The previous prime is 197218919. The next prime is 197218961. The reversal of 197218939 is 939812791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 197218939 - 2⁵ = 197218907 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 197218892 and 197218901.

It is not an unprimeable number, because it can be changed into a prime (197218919) 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, 129507 + ... + 131020.

It is an arithmetic number, because the mean of its divisors is an integer number (49370056).

Almost surely, 2^197218939 is an apocalyptic number.

197218939 is a deficient number, since it is larger than the sum of its proper divisors (261285).

197218939 is an equidigital number, since it uses as much as digits as its factorization.

197218939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261284.

The product of its digits is 244944, while the sum is 49.

The square root of 197218939 is about 14043.4660607700. The cubic root of 197218939 is about 582.0802617587.

The spelling of 197218939 in words is "one hundred ninety-seven million, two hundred eighteen thousand, nine hundred thirty-nine".