1639171977856 has 48 divisors (see below), whose sum is σ = 3798686988090. Its totient is φ = 702502273536.

The previous prime is 1639171977847. The next prime is 1639171977857. The reversal of 1639171977856 is 6587791719361.

It can be written as a sum of positive squares in only one way, i.e., 1448133051456 + 191038926400 = 1203384^2 + 437080^2 .

It is not an unprimeable number, because it can be changed into a prime (1639171977857) 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 5 ways as a sum of consecutive naturals, for example, 130667515 + ... + 130680058.

Almost surely, 2^{1639171977856} is an apocalyptic number.

1639171977856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1639171977856 is an abundant number, since it is smaller than the sum of its proper divisors (2159515010234).

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

1639171977856 is an equidigital number, since it uses as much as digits as its factorization.

1639171977856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261347601 (or 261347582 counting only the distinct ones).

The product of its digits is 120022560, while the sum is 70.

The spelling of 1639171977856 in words is "one trillion, six hundred thirty-nine billion, one hundred seventy-one million, nine hundred seventy-seven thousand, eight hundred fifty-six".