197821371 has 16 divisors (see below), whose sum is σ = 294433920. Its totient is φ = 117102720.

The previous prime is 197821361. The next prime is 197821373. The reversal of 197821371 is 173128791.

It is not a de Polignac number, because 197821371 - 2⁵ = 197821339 is a prime.

It is not an unprimeable number, because it can be changed into a prime (197821373) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68286 + ... + 71123.

It is an arithmetic number, because the mean of its divisors is an integer number (18402120).

Almost surely, 2^197821371 is an apocalyptic number.

197821371 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

197821371 is a deficient number, since it is larger than the sum of its proper divisors (96612549).

197821371 is a wasteful number, since it uses less digits than its factorization.

197821371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139466.

The product of its digits is 21168, while the sum is 39.

The square root of 197821371 is about 14064.8985421154. The cubic root of 197821371 is about 582.6723403435.

The spelling of 197821371 in words is "one hundred ninety-seven million, eight hundred twenty-one thousand, three hundred seventy-one".