238321981 has 2 divisors, whose sum is σ = 238321982. Its totient is φ = 238321980.

The previous prime is 238321943. The next prime is 238321987. The reversal of 238321981 is 189123832.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 218152900 + 20169081 = 14770^2 + 4491^2 .

It is a cyclic number.

It is not a de Polignac number, because 238321981 - 2¹¹ = 238319933 is a prime.

It is a super-2 number, since 2×238321981² = 113594733255528722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 238321981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (238321987) 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, 119160990 + 119160991.

It is an arithmetic number, because the mean of its divisors is an integer number (119160991).

Almost surely, 2^238321981 is an apocalyptic number.

It is an amenable number.

238321981 is a deficient number, since it is larger than the sum of its proper divisors (1).

238321981 is an equidigital number, since it uses as much as digits as its factorization.

238321981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 37.

The square root of 238321981 is about 15437.6805576485. The cubic root of 238321981 is about 619.9947805665.

The spelling of 238321981 in words is "two hundred thirty-eight million, three hundred twenty-one thousand, nine hundred eighty-one".