385559981 has 2 divisors, whose sum is σ = 385559982. Its totient is φ = 385559980.

The previous prime is 385559963. The next prime is 385560011. The reversal of 385559981 is 189955583.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 193488100 + 192071881 = 13910^2 + 13859^2 .

It is a cyclic number.

It is not a de Polignac number, because 385559981 - 2⁶ = 385559917 is a prime.

It is a super-2 number, since 2×385559981² = 297312997897440722, which contains 22 as substring.

It is a Sophie Germain 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 (385559081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192779990 + 192779991.

It is an arithmetic number, because the mean of its divisors is an integer number (192779991).

Almost surely, 2^385559981 is an apocalyptic number.

It is an amenable number.

385559981 is a deficient number, since it is larger than the sum of its proper divisors (1).

385559981 is an equidigital number, since it uses as much as digits as its factorization.

385559981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944000, while the sum is 53.

The square root of 385559981 is about 19635.6813225312. The cubic root of 385559981 is about 727.8311689612.

It can be divided in two parts, 3855 and 59981, that added together give a palindrome (63836).

The spelling of 385559981 in words is "three hundred eighty-five million, five hundred fifty-nine thousand, nine hundred eighty-one".