1388085660 has 240 divisors, whose sum is σ = 4937671200. Its totient is φ = 323606016.

The previous prime is 1388085653. The next prime is 1388085661. The reversal of 1388085660 is 665808831.

1388085660 is a `hidden beast` number, since 1 + 3 + 8 + 80 + 8 + 566 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388085661) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 398406 + ... + 401874.

It is an arithmetic number, because the mean of its divisors is an integer number (20573630).

Almost surely, 2^1388085660 is an apocalyptic number.

1388085660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1388085660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2468835600).

1388085660 is an abundant number, since it is smaller than the sum of its proper divisors (3549585540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1388085660 is a wasteful number, since it uses less digits than its factorization.

1388085660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3522 (or 3511 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The square root of 1388085660 is about 37257.0216200920. The cubic root of 1388085660 is about 1115.5064588404.

The spelling of 1388085660 in words is "one billion, three hundred eighty-eight million, eighty-five thousand, six hundred sixty".