388640155 has 32 divisors (see below), whose sum is σ = 502364160. Its totient is φ = 287763840.

The previous prime is 388640143. The next prime is 388640167. The reversal of 388640155 is 551046883.

It is an interprime number because it is at equal distance from previous prime (388640143) and next prime (388640167).

It is not a de Polignac number, because 388640155 - 2¹⁷ = 388509083 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1058782 + ... + 1059148.

It is an arithmetic number, because the mean of its divisors is an integer number (15698880).

Almost surely, 2^388640155 is an apocalyptic number.

388640155 is a deficient number, since it is larger than the sum of its proper divisors (113724005).

388640155 is a wasteful number, since it uses less digits than its factorization.

388640155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619.

The product of its (nonzero) digits is 115200, while the sum is 40.

The square root of 388640155 is about 19713.9583797877. The cubic root of 388640155 is about 729.7642041971.

The spelling of 388640155 in words is "three hundred eighty-eight million, six hundred forty thousand, one hundred fifty-five".