21221222101 has 8 divisors (see below), whose sum is σ = 21741088824. Its totient is φ = 20705780160.

The previous prime is 21221222083. The next prime is 21221222123. The reversal of 21221222101 is 10122212212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3069049201 + 18152172900 = 55399^2 + 134730^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221222101 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 (21221222131) 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 7 ways as a sum of consecutive naturals, for example, 1096486 + ... + 1115671.

It is an arithmetic number, because the mean of its divisors is an integer number (2717636103).

Almost surely, 2^21221222101 is an apocalyptic number.

It is an amenable number.

21221222101 is a deficient number, since it is larger than the sum of its proper divisors (519866723).

21221222101 is a wasteful number, since it uses less digits than its factorization.

21221222101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2212391.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21221222101 its reverse (10122212212), we get a palindrome (31343434313).

It can be divided in two parts, 21 and 221222101, that added together give a palindrome (221222122).

The spelling of 21221222101 in words is "twenty-one billion, two hundred twenty-one million, two hundred twenty-two thousand, one hundred one".