1385009280 has 160 divisors (see below), whose sum is σ = 4946303340. Its totient is φ = 369321984.

The previous prime is 1385009279. The next prime is 1385009321. The reversal of 1385009280 is 829005831.

It can be written as a sum of positive squares in 2 ways, for example, as 1311598656 + 73410624 = 36216^2 + 8568^2 .

It is a tau number, because it is divible by the number of its divisors (160).

It is a super-2 number, since 2×1385009280² = 3836501411372236800, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 38482 + ... + 65198.

Almost surely, 2^1385009280 is an apocalyptic number.

1385009280 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 1385009280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2473151670).

1385009280 is an abundant number, since it is smaller than the sum of its proper divisors (3561294060).

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

1385009280 is an equidigital number, since it uses as much as digits as its factorization.

1385009280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26748 (or 26727 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 1385009280 is about 37215.7128105858. The cubic root of 1385009280 is about 1114.6817594725.

The spelling of 1385009280 in words is "one billion, three hundred eighty-five million, nine thousand, two hundred eighty".