2117921019681 has 16 divisors (see below), whose sum is σ = 2990074392000. Its totient is φ = 1328861288448.

The previous prime is 2117921019659. The next prime is 2117921019713. The reversal of 2117921019681 is 1869101297112.

It is not a de Polignac number, because 2117921019681 - 2⁹ = 2117921019169 is a prime.

It is a super-2 number, since 2×2117921019681² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2117921019681.

It is not an unprimeable number, because it can be changed into a prime (2117921019601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1897590 + ... + 2799408.

It is an arithmetic number, because the mean of its divisors is an integer number (186879649500).

Almost surely, 2^{2117921019681} is an apocalyptic number.

It is an amenable number.

2117921019681 is a deficient number, since it is larger than the sum of its proper divisors (872153372319).

2117921019681 is a wasteful number, since it uses less digits than its factorization.

2117921019681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 947888.

The product of its (nonzero) digits is 108864, while the sum is 48.

The spelling of 2117921019681 in words is "two trillion, one hundred seventeen billion, nine hundred twenty-one million, nineteen thousand, six hundred eighty-one".