197864251 has 4 divisors (see below), whose sum is σ = 213084592. Its totient is φ = 182643912.

The previous prime is 197864231. The next prime is 197864257. The reversal of 197864251 is 152468791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 152468791 = 41 ⋅3718751.

It is a cyclic number.

It is not a de Polignac number, because 197864251 - 2¹⁵ = 197831483 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 197864198 and 197864207.

It is not an unprimeable number, because it can be changed into a prime (197864257) 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 3 ways as a sum of consecutive naturals, for example, 7610151 + ... + 7610176.

It is an arithmetic number, because the mean of its divisors is an integer number (53271148).

Almost surely, 2^197864251 is an apocalyptic number.

197864251 is a deficient number, since it is larger than the sum of its proper divisors (15220341).

197864251 is a wasteful number, since it uses less digits than its factorization.

197864251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15220340.

The product of its digits is 120960, while the sum is 43.

The square root of 197864251 is about 14066.4228217411. The cubic root of 197864251 is about 582.7144375561.

The spelling of 197864251 in words is "one hundred ninety-seven million, eight hundred sixty-four thousand, two hundred fifty-one".