1388864840 has 32 divisors (see below), whose sum is σ = 3409032960. Its totient is φ = 505041600.

The previous prime is 1388864833. The next prime is 1388864843. The reversal of 1388864840 is 484688831.

It is not an unprimeable number, because it can be changed into a prime (1388864843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1577816 + ... + 1578695.

It is an arithmetic number, because the mean of its divisors is an integer number (106532280).

Almost surely, 2^1388864840 is an apocalyptic number.

1388864840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1388864840 is an abundant number, since it is smaller than the sum of its proper divisors (2020168120).

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

1388864840 is a wasteful number, since it uses less digits than its factorization.

1388864840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3156533 (or 3156529 counting only the distinct ones).

The product of its (nonzero) digits is 1179648, while the sum is 50.

The square root of 1388864840 is about 37267.4769738978. The cubic root of 1388864840 is about 1115.7151437857.

The spelling of 1388864840 in words is "one billion, three hundred eighty-eight million, eight hundred sixty-four thousand, eight hundred forty".