197025281821 has 4 divisors (see below), whose sum is σ = 197026203132. Its totient is φ = 197024360512.

The previous prime is 197025281689. The next prime is 197025281899. The reversal of 197025281821 is 128182520791.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 74714208921 + 122311072900 = 273339^2 + 349730^2 .

It is a cyclic number.

It is not a de Polignac number, because 197025281821 - 2¹⁹ = 197024757533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197025261821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45531 + ... + 629383.

It is an arithmetic number, because the mean of its divisors is an integer number (49256550783).

Almost surely, 2^197025281821 is an apocalyptic number.

It is an amenable number.

197025281821 is a deficient number, since it is larger than the sum of its proper divisors (921311).

197025281821 is an equidigital number, since it uses as much as digits as its factorization.

197025281821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921310.

The product of its (nonzero) digits is 161280, while the sum is 46.

The spelling of 197025281821 in words is "one hundred ninety-seven billion, twenty-five million, two hundred eighty-one thousand, eight hundred twenty-one".