21244210121 has 16 divisors (see below), whose sum is σ = 21972046848. Its totient is φ = 20531491200.

The previous prime is 21244210103. The next prime is 21244210177. The reversal of 21244210121 is 12101244212.

It is a cyclic number.

It is not a de Polignac number, because 21244210121 - 2¹⁰ = 21244209097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21244210093 and 21244210102.

It is not an unprimeable number, because it can be changed into a prime (21244216121) 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 15 ways as a sum of consecutive naturals, for example, 922811 + ... + 945551.

It is an arithmetic number, because the mean of its divisors is an integer number (1373252928).

Almost surely, 2^21244210121 is an apocalyptic number.

It is an amenable number.

21244210121 is a deficient number, since it is larger than the sum of its proper divisors (727836727).

21244210121 is a wasteful number, since it uses less digits than its factorization.

21244210121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23072.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21244210121 its reverse (12101244212), we get a palindrome (33345454333).

The spelling of 21244210121 in words is "twenty-one billion, two hundred forty-four million, two hundred ten thousand, one hundred twenty-one".