388931 has 2 divisors, whose sum is σ = 388932. Its totient is φ = 388930.

The previous prime is 388903. The next prime is 388933. The reversal of 388931 is 139883.

It is a strong prime.

It is an emirp because it is prime and its reverse (139883) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-388931 is a prime.

It is a super-2 number, since 2×388931² = 302534645522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 388933, it forms a pair of twin primes.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 388931.

It is not a weakly prime, because it can be changed into another prime (388933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194465 + 194466.

It is an arithmetic number, because the mean of its divisors is an integer number (194466).

2³⁸⁸⁹³¹ is an apocalyptic number.

388931 is a deficient number, since it is larger than the sum of its proper divisors (1).

388931 is an equidigital number, since it uses as much as digits as its factorization.

388931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 32.

The square root of 388931 is about 623.6433275519. The cubic root of 388931 is about 72.9946202328.

The spelling of 388931 in words is "three hundred eighty-eight thousand, nine hundred thirty-one".