21221010022001 has 2 divisors, whose sum is σ = 21221010022002. Its totient is φ = 21221010022000.

The previous prime is 21221010021989. The next prime is 21221010022057. The reversal of 21221010022001 is 10022001012212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16555621699600 + 4665388322401 = 4068860^2 + 2159951^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221010022001 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21221010024001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610505011000 + 10610505011001.

It is an arithmetic number, because the mean of its divisors is an integer number (10610505011001).

Almost surely, 2^{21221010022001} is an apocalyptic number.

It is an amenable number.

21221010022001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221010022001 is an equidigital number, since it uses as much as digits as its factorization.

21221010022001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21221010022001 its reverse (10022001012212), we get a palindrome (31243011034213).

The spelling of 21221010022001 in words is "twenty-one trillion, two hundred twenty-one billion, ten million, twenty-two thousand, one".