197047821 has 4 divisors (see below), whose sum is σ = 262730432. Its totient is φ = 131365212.

The previous prime is 197047819. The next prime is 197047847. The reversal of 197047821 is 128740791.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 197047821 - 2¹ = 197047819 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 197047821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197047861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32841301 + ... + 32841306.

It is an arithmetic number, because the mean of its divisors is an integer number (65682608).

Almost surely, 2^197047821 is an apocalyptic number.

It is an amenable number.

197047821 is a deficient number, since it is larger than the sum of its proper divisors (65682611).

197047821 is an equidigital number, since it uses as much as digits as its factorization.

197047821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65682610.

The product of its (nonzero) digits is 28224, while the sum is 39.

The square root of 197047821 is about 14037.3722968368. The cubic root of 197047821 is about 581.9118647612.

The spelling of 197047821 in words is "one hundred ninety-seven million, forty-seven thousand, eight hundred twenty-one".