228653356821 has 4 divisors (see below), whose sum is σ = 304871142432. Its totient is φ = 152435571212.

The previous prime is 228653356793. The next prime is 228653356889. The reversal of 228653356821 is 128653356822.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-228653356821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228653356621) 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, 38108892801 + ... + 38108892806.

It is an arithmetic number, because the mean of its divisors is an integer number (76217785608).

Almost surely, 2^228653356821 is an apocalyptic number.

It is an amenable number.

228653356821 is a deficient number, since it is larger than the sum of its proper divisors (76217785611).

228653356821 is an equidigital number, since it uses as much as digits as its factorization.

228653356821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76217785610.

The product of its digits is 4147200, while the sum is 51.

Subtracting from 228653356821 its reverse (128653356822), we obtain a palindrome (99999999999).

The spelling of 228653356821 in words is "two hundred twenty-eight billion, six hundred fifty-three million, three hundred fifty-six thousand, eight hundred twenty-one".