20661751101 has 16 divisors (see below), whose sum is σ = 27832645568. Its totient is φ = 13633401600.

The previous prime is 20661751021. The next prime is 20661751129. The reversal of 20661751101 is 10115716602.

It is not a de Polignac number, because 20661751101 - 2⁷ = 20661750973 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661351101) 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 15 ways as a sum of consecutive naturals, for example, 24405 + ... + 204741.

It is an arithmetic number, because the mean of its divisors is an integer number (1739540348).

Almost surely, 2^20661751101 is an apocalyptic number.

It is an amenable number.

20661751101 is a deficient number, since it is larger than the sum of its proper divisors (7170894467).

20661751101 is a wasteful number, since it uses less digits than its factorization.

20661751101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180732.

The product of its (nonzero) digits is 2520, while the sum is 30.

The spelling of 20661751101 in words is "twenty billion, six hundred sixty-one million, seven hundred fifty-one thousand, one hundred one".