10821888221 has 4 divisors (see below), whose sum is σ = 10836298944. Its totient is φ = 10807477500.

The previous prime is 10821888151. The next prime is 10821888223. The reversal of 10821888221 is 12288812801.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12288812801 = 157 ⋅78272693.

It is a cyclic number.

It is not a de Polignac number, because 10821888221 - 2¹⁸ = 10821626077 is a prime.

It is a super-2 number, since 2×10821888221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10821888223) 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, 7204235 + ... + 7205736.

It is an arithmetic number, because the mean of its divisors is an integer number (2709074736).

Almost surely, 2^10821888221 is an apocalyptic number.

It is an amenable number.

10821888221 is a deficient number, since it is larger than the sum of its proper divisors (14410723).

10821888221 is an equidigital number, since it uses as much as digits as its factorization.

10821888221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14410722.

The product of its (nonzero) digits is 32768, while the sum is 41.

The spelling of 10821888221 in words is "ten billion, eight hundred twenty-one million, eight hundred eighty-eight thousand, two hundred twenty-one".