197666555 has 16 divisors (see below), whose sum is σ = 240033024. Its totient is φ = 156255840.

The previous prime is 197666507. The next prime is 197666569. The reversal of 197666555 is 555666791.

It is not a de Polignac number, because 197666555 - 2¹⁸ = 197404411 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 200594 + ... + 201576.

It is an arithmetic number, because the mean of its divisors is an integer number (15002064).

Almost surely, 2^197666555 is an apocalyptic number.

197666555 is a deficient number, since it is larger than the sum of its proper divisors (42366469).

197666555 is a wasteful number, since it uses less digits than its factorization.

197666555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426.

The product of its digits is 1701000, while the sum is 50.

The square root of 197666555 is about 14059.3938347284. The cubic root of 197666555 is about 582.5202999059.

The spelling of 197666555 in words is "one hundred ninety-seven million, six hundred sixty-six thousand, five hundred fifty-five".