238165021 has 2 divisors, whose sum is σ = 238165022. Its totient is φ = 238165020.

The previous prime is 238165007. The next prime is 238165051. The reversal of 238165021 is 120561832.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 217562500 + 20602521 = 14750^2 + 4539^2 .

It is a cyclic number.

It is not a de Polignac number, because 238165021 - 2¹³ = 238156829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (238165001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 119082510 + 119082511.

It is an arithmetic number, because the mean of its divisors is an integer number (119082511).

Almost surely, 2^238165021 is an apocalyptic number.

It is an amenable number.

238165021 is a deficient number, since it is larger than the sum of its proper divisors (1).

238165021 is an equidigital number, since it uses as much as digits as its factorization.

238165021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 238165021 is about 15432.5960551036. The cubic root of 238165021 is about 619.8586401623.

The spelling of 238165021 in words is "two hundred thirty-eight million, one hundred sixty-five thousand, twenty-one".