20371321 has 6 divisors (see below), whose sum is σ = 21640430. Its totient is φ = 19172736.

The previous prime is 20371319. The next prime is 20371327. The reversal of 20371321 is 12317302.

It can be written as a sum of positive squares in 3 ways, for example, as 3240000 + 17131321 = 1800^2 + 4139^2 .

It is not a de Polignac number, because 20371321 - 2¹ = 20371319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20371327) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34956 + ... + 35533.

Almost surely, 2^20371321 is an apocalyptic number.

It is an amenable number.

20371321 is a deficient number, since it is larger than the sum of its proper divisors (1269109).

20371321 is an equidigital number, since it uses as much as digits as its factorization.

20371321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70523 (or 70506 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 20371321 is about 4513.4599809902. The cubic root of 20371321 is about 273.1113385218. Note that the first 3 decimals are identical.

Adding to 20371321 its reverse (12317302), we get a palindrome (32688623).

The spelling of 20371321 in words is "twenty million, three hundred seventy-one thousand, three hundred twenty-one".