21020020337 has 2 divisors, whose sum is σ = 21020020338. Its totient is φ = 21020020336.

The previous prime is 21020020319. The next prime is 21020020387. The reversal of 21020020337 is 73302002012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19894820401 + 1125199936 = 141049^2 + 33544^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020020337 - 2¹⁰ = 21020019313 is a prime.

It is not a weakly prime, because it can be changed into another prime (21020020387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510010168 + 10510010169.

It is an arithmetic number, because the mean of its divisors is an integer number (10510010169).

Almost surely, 2^21020020337 is an apocalyptic number.

It is an amenable number.

21020020337 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020020337 is an equidigital number, since it uses as much as digits as its factorization.

21020020337 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 20.

Adding to 21020020337 its reverse (73302002012), we get a palindrome (94322022349).

The spelling of 21020020337 in words is "twenty-one billion, twenty million, twenty thousand, three hundred thirty-seven".