388870409 has 2 divisors, whose sum is σ = 388870410. Its totient is φ = 388870408.

The previous prime is 388870379. The next prime is 388870411. The reversal of 388870409 is 904078883.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 286557184 + 102313225 = 16928^2 + 10115^2 .

It is an emirp because it is prime and its reverse (904078883) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-388870409 is a prime.

Together with 388870411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (388870429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194435204 + 194435205.

It is an arithmetic number, because the mean of its divisors is an integer number (194435205).

Almost surely, 2^388870409 is an apocalyptic number.

It is an amenable number.

388870409 is a deficient number, since it is larger than the sum of its proper divisors (1).

388870409 is an equidigital number, since it uses as much as digits as its factorization.

388870409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 387072, while the sum is 47.

The square root of 388870409 is about 19719.7973873973. The cubic root of 388870409 is about 729.9082946038.

The spelling of 388870409 in words is "three hundred eighty-eight million, eight hundred seventy thousand, four hundred nine".