1636396381872 has 90 divisors (see below), whose sum is σ = 5327332971948. Its totient is φ = 467541821376.

The previous prime is 1636396381853. The next prime is 1636396381877. The reversal of 1636396381872 is 2781836936361.

1636396381872 is a `hidden beast` number, since 1 + 6 + 36 + 396 + 38 + 187 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1636396381877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 115950738 + ... + 115964849.

Almost surely, 2^{1636396381872} is an apocalyptic number.

1636396381872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1636396381872 is an abundant number, since it is smaller than the sum of its proper divisors (3690936590076).

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

1636396381872 is a wasteful number, since it uses less digits than its factorization.

1636396381872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231915615 (or 231915599 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 63.

The spelling of 1636396381872 in words is "one trillion, six hundred thirty-six billion, three hundred ninety-six million, three hundred eighty-one thousand, eight hundred seventy-two".