1388401920 has 216 divisors, whose sum is σ = 4836529152. Its totient is φ = 367718400.

The previous prime is 1388401909. The next prime is 1388401981. The reversal of 1388401920 is 291048831.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2200005 + ... + 2200635.

Almost surely, 2^1388401920 is an apocalyptic number.

1388401920 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 1388401920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2418264576).

1388401920 is an abundant number, since it is smaller than the sum of its proper divisors (3448127232).

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

1388401920 is a wasteful number, since it uses less digits than its factorization.

1388401920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 849 (or 832 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 1388401920 is about 37261.2656789863. The cubic root of 1388401920 is about 1115.5911710195.

The spelling of 1388401920 in words is "one billion, three hundred eighty-eight million, four hundred one thousand, nine hundred twenty".