388288781 has 2 divisors, whose sum is σ = 388288782. Its totient is φ = 388288780.

The previous prime is 388288763. The next prime is 388288811. The reversal of 388288781 is 187882883.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 326524900 + 61763881 = 18070^2 + 7859^2 .

It is a cyclic number.

It is not a de Polignac number, because 388288781 - 2¹⁴ = 388272397 is a prime.

It is a super-2 number, since 2×388288781² = 301536354900931922, 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 (388288711) 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, 194144390 + 194144391.

It is an arithmetic number, because the mean of its divisors is an integer number (194144391).

Almost surely, 2^388288781 is an apocalyptic number.

It is an amenable number.

388288781 is a deficient number, since it is larger than the sum of its proper divisors (1).

388288781 is an equidigital number, since it uses as much as digits as its factorization.

388288781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1376256, while the sum is 53.

The square root of 388288781 is about 19705.0445571686. The cubic root of 388288781 is about 729.5442085014.

The spelling of 388288781 in words is "three hundred eighty-eight million, two hundred eighty-eight thousand, seven hundred eighty-one".