21420031001 has 2 divisors, whose sum is σ = 21420031002. Its totient is φ = 21420031000.

The previous prime is 21420030977. The next prime is 21420031057. The reversal of 21420031001 is 10013002412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16880505625 + 4539525376 = 129925^2 + 67376^2 .

It is a cyclic number.

It is not a de Polignac number, because 21420031001 - 2¹⁴ = 21420014617 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 (21420034001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710015500 + 10710015501.

It is an arithmetic number, because the mean of its divisors is an integer number (10710015501).

Almost surely, 2^21420031001 is an apocalyptic number.

It is an amenable number.

21420031001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21420031001 is an equidigital number, since it uses as much as digits as its factorization.

21420031001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21420031001 its reverse (10013002412), we get a palindrome (31433033413).

The spelling of 21420031001 in words is "twenty-one billion, four hundred twenty million, thirty-one thousand, one".