197821855 has 32 divisors (see below), whose sum is σ = 300418560. Its totient is φ = 121461120.

The previous prime is 197821849. The next prime is 197821861. The reversal of 197821855 is 558128791.

It is an interprime number because it is at equal distance from previous prime (197821849) and next prime (197821861).

It is not a de Polignac number, because 197821855 - 2⁹ = 197821343 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21961 + ... + 29629.

It is an arithmetic number, because the mean of its divisors is an integer number (9388080).

Almost surely, 2^197821855 is an apocalyptic number.

197821855 is a deficient number, since it is larger than the sum of its proper divisors (102596705).

197821855 is a wasteful number, since it uses less digits than its factorization.

197821855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7759.

The product of its digits is 201600, while the sum is 46.

The square root of 197821855 is about 14064.9157480591. The cubic root of 197821855 is about 582.6728155419.

The spelling of 197821855 in words is "one hundred ninety-seven million, eight hundred twenty-one thousand, eight hundred fifty-five".