2638378240 has 288 divisors, whose sum is σ = 7172232480. Its totient is φ = 924844032.

The previous prime is 2638378207. The next prime is 2638378241. The reversal of 2638378240 is 428738362.

It can be written as a sum of positive squares in 16 ways, for example, as 404492544 + 2233885696 = 20112^2 + 47264^2 .

It is a super-2 number, since 2×2638378240² = 13922079474610995200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2638378241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23348424 + ... + 23348536.

It is an arithmetic number, because the mean of its divisors is an integer number (24903585).

Almost surely, 2^2638378240 is an apocalyptic number.

2638378240 is a gapful number since it is divisible by the number (20) 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 2638378240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3586116240).

2638378240 is an abundant number, since it is smaller than the sum of its proper divisors (4533854240).

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

2638378240 is a wasteful number, since it uses less digits than its factorization.

2638378240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 43.

The square root of 2638378240 is about 51365.1461596285. The cubic root of 2638378240 is about 1381.8015817699.

The spelling of 2638378240 in words is "two billion, six hundred thirty-eight million, three hundred seventy-eight thousand, two hundred forty".