384638981 has 2 divisors, whose sum is σ = 384638982. Its totient is φ = 384638980.

The previous prime is 384638953. The next prime is 384638987. The reversal of 384638981 is 189836483.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 248566756 + 136072225 = 15766^2 + 11665^2 .

It is a cyclic number.

It is not a de Polignac number, because 384638981 - 2¹⁴ = 384622597 is a prime.

It is a super-2 number, since 2×384638981² = 295894291409436722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (384638987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192319490 + 192319491.

It is an arithmetic number, because the mean of its divisors is an integer number (192319491).

Almost surely, 2^384638981 is an apocalyptic number.

It is an amenable number.

384638981 is a deficient number, since it is larger than the sum of its proper divisors (1).

384638981 is an equidigital number, since it uses as much as digits as its factorization.

384638981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 995328, while the sum is 50.

The square root of 384638981 is about 19612.2150967197. The cubic root of 384638981 is about 727.2511753609.

The spelling of 384638981 in words is "three hundred eighty-four million, six hundred thirty-eight thousand, nine hundred eighty-one".