21220021002001 has 2 divisors, whose sum is σ = 21220021002002. Its totient is φ = 21220021002000.

The previous prime is 21220021001939. The next prime is 21220021002017. The reversal of 21220021002001 is 10020012002212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19519607610000 + 1700413392001 = 4418100^2 + 1303999^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220021002001 - 2³⁷ = 21082582048529 is a prime.

It is not a weakly prime, because it can be changed into another prime (21220021002601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610010501000 + 10610010501001.

It is an arithmetic number, because the mean of its divisors is an integer number (10610010501001).

Almost surely, 2^{21220021002001} is an apocalyptic number.

It is an amenable number.

21220021002001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220021002001 is an equidigital number, since it uses as much as digits as its factorization.

21220021002001 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 13.

Adding to 21220021002001 its reverse (10020012002212), we get a palindrome (31240033004213).

The spelling of 21220021002001 in words is "twenty-one trillion, two hundred twenty billion, twenty-one million, two thousand, one".