197155999 has 2 divisors, whose sum is σ = 197156000. Its totient is φ = 197155998.

The previous prime is 197155997. The next prime is 197156041. The reversal of 197155999 is 999551791.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 197155999 - 2¹ = 197155997 is a prime.

Together with 197155997, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197155997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98577999 + 98578000.

It is an arithmetic number, because the mean of its divisors is an integer number (98578000).

Almost surely, 2^197155999 is an apocalyptic number.

197155999 is a deficient number, since it is larger than the sum of its proper divisors (1).

197155999 is an equidigital number, since it uses as much as digits as its factorization.

197155999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1148175, while the sum is 55.

The square root of 197155999 is about 14041.2249821730. The cubic root of 197155999 is about 582.0183339170.

It can be divided in two parts, 1971 and 55999, that added together give a triangular number (57970 = T₃₄₀).

The spelling of 197155999 in words is "one hundred ninety-seven million, one hundred fifty-five thousand, nine hundred ninety-nine".