197153991 has 6 divisors (see below), whose sum is σ = 284778000. Its totient is φ = 131435988.

The previous prime is 197153941. The next prime is 197154031. The reversal of 197153991 is 199351791.

It is a happy number.

It is not a de Polignac number, because 197153991 - 2⁶ = 197153927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197153921) 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 5 ways as a sum of consecutive naturals, for example, 10952991 + ... + 10953008.

It is an arithmetic number, because the mean of its divisors is an integer number (47463000).

Almost surely, 2^197153991 is an apocalyptic number.

197153991 is a deficient number, since it is larger than the sum of its proper divisors (87624009).

197153991 is a wasteful number, since it uses less digits than its factorization.

197153991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21906005 (or 21906002 counting only the distinct ones).

The product of its digits is 76545, while the sum is 45.

The square root of 197153991 is about 14041.1534782581. The cubic root of 197153991 is about 582.0163579914.

The spelling of 197153991 in words is "one hundred ninety-seven million, one hundred fifty-three thousand, nine hundred ninety-one".