1388390550 has 48 divisors (see below), whose sum is σ = 3459605952. Its totient is φ = 368474400.

The previous prime is 1388390467. The next prime is 1388390569. The reversal of 1388390550 is 550938831.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

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, 9717 + ... + 53583.

It is an arithmetic number, because the mean of its divisors is an integer number (72075124).

Almost surely, 2^1388390550 is an apocalyptic number.

1388390550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1388390550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1729802976).

1388390550 is an abundant number, since it is smaller than the sum of its proper divisors (2071215402).

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

1388390550 is a wasteful number, since it uses less digits than its factorization.

1388390550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44093 (or 44088 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 42.

The square root of 1388390550 is about 37261.1131073670. The cubic root of 1388390550 is about 1115.5881257183.

The spelling of 1388390550 in words is "one billion, three hundred eighty-eight million, three hundred ninety thousand, five hundred fifty".