388721065 has 16 divisors (see below), whose sum is σ = 494437392. Its totient is φ = 292368384.

The previous prime is 388721063. The next prime is 388721111. The reversal of 388721065 is 560127883.

It can be written as a sum of positive squares in 8 ways, for example, as 355216 + 388365849 = 596^2 + 19707^2 .

It is a cyclic number.

It is not a de Polignac number, because 388721065 - 2¹ = 388721063 is a prime.

It is a super-2 number, since 2×388721065² = 302208132749468450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (388721063) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103297 + ... + 106993.

It is an arithmetic number, because the mean of its divisors is an integer number (30902337).

Almost surely, 2^388721065 is an apocalyptic number.

It is an amenable number.

388721065 is a deficient number, since it is larger than the sum of its proper divisors (105716327).

388721065 is a wasteful number, since it uses less digits than its factorization.

388721065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4956.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 388721065 is about 19716.0103722837. The cubic root of 388721065 is about 729.8148432642.

The spelling of 388721065 in words is "three hundred eighty-eight million, seven hundred twenty-one thousand, sixty-five".