197155987 has 8 divisors (see below), whose sum is σ = 238575456. Its totient is φ = 159050112.

The previous prime is 197155963. The next prime is 197155997. The reversal of 197155987 is 789551791.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-197155987 is a prime.

It is not an unprimeable number, because it can be changed into a prime (197155927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 828268 + ... + 828505.

It is an arithmetic number, because the mean of its divisors is an integer number (29821932).

Almost surely, 2^197155987 is an apocalyptic number.

197155987 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

197155987 is a deficient number, since it is larger than the sum of its proper divisors (41419469).

197155987 is a wasteful number, since it uses less digits than its factorization.

197155987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1656797.

The product of its digits is 793800, while the sum is 52.

The square root of 197155987 is about 14041.2245548599. The cubic root of 197155987 is about 582.0183221087.

The spelling of 197155987 in words is "one hundred ninety-seven million, one hundred fifty-five thousand, nine hundred eighty-seven".