388781 has 2 divisors, whose sum is σ = 388782. Its totient is φ = 388780.

The previous prime is 388777. The next prime is 388789. The reversal of 388781 is 187883.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 292681 + 96100 = 541^2 + 310^2 .

It is an emirp because it is prime and its reverse (187883) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 388781 - 2² = 388777 is a prime.

It is a super-2 number, since 2×388781² = 302301331922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (388789) 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, 194390 + 194391.

It is an arithmetic number, because the mean of its divisors is an integer number (194391).

2³⁸⁸⁷⁸¹ is an apocalyptic number.

It is an amenable number.

388781 is a deficient number, since it is larger than the sum of its proper divisors (1).

388781 is an equidigital number, since it uses as much as digits as its factorization.

388781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10752, while the sum is 35.

The square root of 388781 is about 623.5230549066. The cubic root of 388781 is about 72.9852350197.

The spelling of 388781 in words is "three hundred eighty-eight thousand, seven hundred eighty-one".