197997309 has 36 divisors (see below), whose sum is σ = 304609500. Its totient is φ = 123907968.

The previous prime is 197997307. The next prime is 197997329. The reversal of 197997309 is 903799791.

It can be written as a sum of positive squares in 2 ways, for example, as 104101209 + 93896100 = 10203^2 + 9690^2 .

It is not a de Polignac number, because 197997309 - 2¹ = 197997307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197997307) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 483897 + ... + 484305.

It is an arithmetic number, because the mean of its divisors is an integer number (8461375).

Almost surely, 2^197997309 is an apocalyptic number.

197997309 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

197997309 is a deficient number, since it is larger than the sum of its proper divisors (106612191).

197997309 is a wasteful number, since it uses less digits than its factorization.

197997309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602 (or 580 counting only the distinct ones).

The product of its (nonzero) digits is 964467, while the sum is 54.

The square root of 197997309 is about 14071.1516586241. The cubic root of 197997309 is about 582.8450278366.

The spelling of 197997309 in words is "one hundred ninety-seven million, nine hundred ninety-seven thousand, three hundred nine".