21320031001 has 4 divisors (see below), whose sum is σ = 21320425252. Its totient is φ = 21319636752.

The previous prime is 21320030999. The next prime is 21320031013. The reversal of 21320031001 is 10013002312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17642214976 + 3677816025 = 132824^2 + 60645^2 .

It is a cyclic number.

It is not a de Polignac number, because 21320031001 - 2¹ = 21320030999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21320031071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100086 + ... + 229471.

It is an arithmetic number, because the mean of its divisors is an integer number (5330106313).

Almost surely, 2^21320031001 is an apocalyptic number.

It is an amenable number.

21320031001 is a deficient number, since it is larger than the sum of its proper divisors (394251).

21320031001 is an equidigital number, since it uses as much as digits as its factorization.

21320031001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394250.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 21320031001 its reverse (10013002312), we get a palindrome (31333033313).

The spelling of 21320031001 in words is "twenty-one billion, three hundred twenty million, thirty-one thousand, one".