21130021001 has 2 divisors, whose sum is σ = 21130021002. Its totient is φ = 21130021000.

The previous prime is 21130020943. The next prime is 21130021009. The reversal of 21130021001 is 10012003112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21129529600 + 491401 = 145360^2 + 701^2 .

It is a cyclic number.

It is not a de Polignac number, because 21130021001 - 2¹⁸ = 21129758857 is a prime.

It is not a weakly prime, because it can be changed into another prime (21130021009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565010500 + 10565010501.

It is an arithmetic number, because the mean of its divisors is an integer number (10565010501).

Almost surely, 2^21130021001 is an apocalyptic number.

It is an amenable number.

21130021001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130021001 is an equidigital number, since it uses as much as digits as its factorization.

21130021001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21130021001 its reverse (10012003112), we get a palindrome (31142024113).

The spelling of 21130021001 in words is "twenty-one billion, one hundred thirty million, twenty-one thousand, one".