1636780128768 has 120 divisors (see below), whose sum is σ = 4724432512800. Its totient is φ = 545527056384.

The previous prime is 1636780128713. The next prime is 1636780128793. The reversal of 1636780128768 is 8678210876361.

1636780128768 is a `hidden beast` number, since 1 + 6 + 367 + 80 + 128 + 76 + 8 = 666.

It is a super-2 number, since 2×1636780128768² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50943813 + ... + 50975931.

It is an arithmetic number, because the mean of its divisors is an integer number (39370270940).

Almost surely, 2^{1636780128768} is an apocalyptic number.

1636780128768 is a gapful number since it is divisible by the number (18) 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 1636780128768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2362216256400).

1636780128768 is an abundant number, since it is smaller than the sum of its proper divisors (3087652384032).

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

1636780128768 is a wasteful number, since it uses less digits than its factorization.

1636780128768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43202 (or 43183 counting only the distinct ones).

The product of its (nonzero) digits is 32514048, while the sum is 63.

The spelling of 1636780128768 in words is "one trillion, six hundred thirty-six billion, seven hundred eighty million, one hundred twenty-eight thousand, seven hundred sixty-eight".