2051638138368 has 960 divisors, whose sum is σ = 7458974595072. Its totient is φ = 528523591680.

The previous prime is 2051638138367. The next prime is 2051638138453. The reversal of 2051638138368 is 8638318361502.

2051638138368 is a `hidden beast` number, since 2 + 0 + 516 + 38 + 1 + 38 + 3 + 68 = 666.

It is a super-2 number, since 2×2051638138368² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2051638138367) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4078803205 + ... + 4078803707.

Almost surely, 2^{2051638138368} is an apocalyptic number.

2051638138368 is a gapful number since it is divisible by the number (28) 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 2051638138368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3729487297536).

2051638138368 is an abundant number, since it is smaller than the sum of its proper divisors (5407336456704).

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

2051638138368 is a wasteful number, since it uses less digits than its factorization.

2051638138368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 755 (or 736 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 54.

The spelling of 2051638138368 in words is "two trillion, fifty-one billion, six hundred thirty-eight million, one hundred thirty-eight thousand, three hundred sixty-eight".