388400081 has 2 divisors, whose sum is σ = 388400082. Its totient is φ = 388400080.

The previous prime is 388400053. The next prime is 388400087. The reversal of 388400081 is 180004883.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 234243025 + 154157056 = 15305^2 + 12416^2 .

It is a cyclic number.

It is not a de Polignac number, because 388400081 - 2⁶ = 388400017 is a prime.

It is a super-2 number, since 2×388400081² = 301709245841613122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (388400087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194200040 + 194200041.

It is an arithmetic number, because the mean of its divisors is an integer number (194200041).

Almost surely, 2^388400081 is an apocalyptic number.

It is an amenable number.

388400081 is a deficient number, since it is larger than the sum of its proper divisors (1).

388400081 is an equidigital number, since it uses as much as digits as its factorization.

388400081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 388400081 is about 19707.8685047369. The cubic root of 388400081 is about 729.6139079256.

The spelling of 388400081 in words is "three hundred eighty-eight million, four hundred thousand, eighty-one".