388788221 has 2 divisors, whose sum is σ = 388788222. Its totient is φ = 388788220.

The previous prime is 388788209. The next prime is 388788259. The reversal of 388788221 is 122887883.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 372876100 + 15912121 = 19310^2 + 3989^2 .

It is a cyclic number.

It is not a de Polignac number, because 388788221 - 2¹⁸ = 388526077 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (328788221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194394110 + 194394111.

It is an arithmetic number, because the mean of its divisors is an integer number (194394111).

Almost surely, 2^388788221 is an apocalyptic number.

It is an amenable number.

388788221 is a deficient number, since it is larger than the sum of its proper divisors (1).

388788221 is an equidigital number, since it uses as much as digits as its factorization.

388788221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 344064, while the sum is 47.

The square root of 388788221 is about 19717.7133816272. The cubic root of 388788221 is about 729.8568687918.

The spelling of 388788221 in words is "three hundred eighty-eight million, seven hundred eighty-eight thousand, two hundred twenty-one".