21121002217 has 8 divisors (see below), whose sum is σ = 24139619136. Its totient is φ = 18102718032.

The previous prime is 21121002211. The next prime is 21121002233. The reversal of 21121002217 is 71220012112.

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

It is not a de Polignac number, because 21121002217 - 2¹¹ = 21121000169 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21121002194 and 21121002203.

It is not an unprimeable number, because it can be changed into a prime (21121002211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72198 + ... + 217840.

It is an arithmetic number, because the mean of its divisors is an integer number (3017452392).

Almost surely, 2^21121002217 is an apocalyptic number.

It is an amenable number.

21121002217 is a deficient number, since it is larger than the sum of its proper divisors (3018616919).

21121002217 is a wasteful number, since it uses less digits than its factorization.

21121002217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166367.

The product of its (nonzero) digits is 112, while the sum is 19.

Adding to 21121002217 its reverse (71220012112), we get a palindrome (92341014329).

The spelling of 21121002217 in words is "twenty-one billion, one hundred twenty-one million, two thousand, two hundred seventeen".