1639772979768 has 768 divisors, whose sum is σ = 6103665792000. Its totient is φ = 397872414720.

The previous prime is 1639772979743. The next prime is 1639772979773. The reversal of 1639772979768 is 8679792779361.

1639772979768 is a `hidden beast` number, since 1 + 6 + 397 + 72 + 97 + 9 + 76 + 8 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 432313680 + ... + 432317472.

It is an arithmetic number, because the mean of its divisors is an integer number (7947481500).

Almost surely, 2^{1639772979768} is an apocalyptic number.

1639772979768 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 1639772979768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3051832896000).

1639772979768 is an abundant number, since it is smaller than the sum of its proper divisors (4463892812232).

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

1639772979768 is a wasteful number, since it uses less digits than its factorization.

1639772979768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3993 (or 3972 counting only the distinct ones).

The product of its digits is 3024568512, while the sum is 81.

The spelling of 1639772979768 in words is "one trillion, six hundred thirty-nine billion, seven hundred seventy-two million, nine hundred seventy-nine thousand, seven hundred sixty-eight".