388891121 has 2 divisors, whose sum is σ = 388891122. Its totient is φ = 388891120.

The previous prime is 388891067. The next prime is 388891123. The reversal of 388891121 is 121198883.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 357966400 + 30924721 = 18920^2 + 5561^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-388891121 is a prime.

Together with 388891123, 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 (388891123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194445560 + 194445561.

It is an arithmetic number, because the mean of its divisors is an integer number (194445561).

Almost surely, 2^388891121 is an apocalyptic number.

It is an amenable number.

388891121 is a deficient number, since it is larger than the sum of its proper divisors (1).

388891121 is an equidigital number, since it uses as much as digits as its factorization.

388891121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 41.

The square root of 388891121 is about 19720.3225379303. The cubic root of 388891121 is about 729.9212531558.

The spelling of 388891121 in words is "three hundred eighty-eight million, eight hundred ninety-one thousand, one hundred twenty-one".