388669640 has 64 divisors (see below), whose sum is σ = 966245760. Its totient is φ = 139955200.

The previous prime is 388669637. The next prime is 388669679. The reversal of 388669640 is 46966883.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3215 + ... + 28065.

It is an arithmetic number, because the mean of its divisors is an integer number (15097590).

Almost surely, 2^388669640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 388669640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (483122880).

388669640 is an abundant number, since it is smaller than the sum of its proper divisors (577576120).

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

388669640 is a wasteful number, since it uses less digits than its factorization.

388669640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24902 (or 24898 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 50.

The square root of 388669640 is about 19714.7061859922. The cubic root of 388669640 is about 729.7826587607.

The spelling of 388669640 in words is "three hundred eighty-eight million, six hundred sixty-nine thousand, six hundred forty".