2638138680 has 128 divisors (see below), whose sum is σ = 8872027200. Its totient is φ = 697245696.

The previous prime is 2638138673. The next prime is 2638138681. The reversal of 2638138680 is 868318362.

2638138680 is a `hidden beast` number, since 2 + 638 + 1 + 3 + 8 + 6 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2638138681) 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, 111232 + ... + 132848.

Almost surely, 2^2638138680 is an apocalyptic number.

2638138680 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 2638138680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4436013600).

2638138680 is an abundant number, since it is smaller than the sum of its proper divisors (6233888520).

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

2638138680 is a wasteful number, since it uses less digits than its factorization.

2638138680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21750 (or 21740 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 2638138680 is about 51362.8141752377. The cubic root of 2638138680 is about 1381.7597588044.

The spelling of 2638138680 in words is "two billion, six hundred thirty-eight million, one hundred thirty-eight thousand, six hundred eighty".