238340021 has 2 divisors, whose sum is σ = 238340022. Its totient is φ = 238340020.

The previous prime is 238339957. The next prime is 238340023. The reversal of 238340021 is 120043832.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209931121 + 28408900 = 14489^2 + 5330^2 .

It is a cyclic number.

It is not a de Polignac number, because 238340021 - 2⁶ = 238339957 is a prime.

It is a super-2 number, since 2×238340021² = 113611931220560882, which contains 22 as substring.

Together with 238340023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (238340023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 119170010 + 119170011.

It is an arithmetic number, because the mean of its divisors is an integer number (119170011).

Almost surely, 2^238340021 is an apocalyptic number.

It is an amenable number.

238340021 is a deficient number, since it is larger than the sum of its proper divisors (1).

238340021 is an equidigital number, since it uses as much as digits as its factorization.

238340021 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 238340021 is about 15438.2648312561. The cubic root of 238340021 is about 620.0104238622.

Adding to 238340021 its reverse (120043832), we get a palindrome (358383853).

The spelling of 238340021 in words is "two hundred thirty-eight million, three hundred forty thousand, twenty-one".