21221330101 has 4 divisors (see below), whose sum is σ = 21252863212. Its totient is φ = 21189796992.

The previous prime is 21221330089. The next prime is 21221330113. The reversal of 21221330101 is 10103312212.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21221330089) and next prime (21221330113).

It can be written as a sum of positive squares in 2 ways, for example, as 8196586225 + 13024743876 = 90535^2 + 114126^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221330101 - 2¹⁵ = 21221297333 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 (21221333101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15765546 + ... + 15766891.

It is an arithmetic number, because the mean of its divisors is an integer number (5313215803).

Almost surely, 2^21221330101 is an apocalyptic number.

It is an amenable number.

21221330101 is a deficient number, since it is larger than the sum of its proper divisors (31533111).

21221330101 is an equidigital number, since it uses as much as digits as its factorization.

21221330101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31533110.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21221330101 its reverse (10103312212), we get a palindrome (31324642313).

The spelling of 21221330101 in words is "twenty-one billion, two hundred twenty-one million, three hundred thirty thousand, one hundred one".