338420021 has 2 divisors, whose sum is σ = 338420022. Its totient is φ = 338420020.

The previous prime is 338419987. The next prime is 338420051. The reversal of 338420021 is 120024833.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 323100625 + 15319396 = 17975^2 + 3914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-338420021 is a prime.

It is a super-2 number, since 2×338420021² = 229056221227280882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (338420051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 169210010 + 169210011.

It is an arithmetic number, because the mean of its divisors is an integer number (169210011).

Almost surely, 2^338420021 is an apocalyptic number.

It is an amenable number.

338420021 is a deficient number, since it is larger than the sum of its proper divisors (1).

338420021 is an equidigital number, since it uses as much as digits as its factorization.

338420021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 338420021 is about 18396.1958295730. The cubic root of 338420021 is about 696.8703968567.

Adding to 338420021 its reverse (120024833), we get a palindrome (458444854).

The spelling of 338420021 in words is "three hundred thirty-eight million, four hundred twenty thousand, twenty-one".