20661751216 has 20 divisors (see below), whose sum is σ = 40883892192. Its totient is φ = 10111069376.

The previous prime is 20661751177. The next prime is 20661751217. The reversal of 20661751216 is 61215716602.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20661751217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13737115 + ... + 13738618.

Almost surely, 2^20661751216 is an apocalyptic number.

It is an amenable number.

20661751216 is a deficient number, since it is larger than the sum of its proper divisors (20222140976).

20661751216 is a wasteful number, since it uses less digits than its factorization.

20661751216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27475788 (or 27475782 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 37.

The spelling of 20661751216 in words is "twenty billion, six hundred sixty-one million, seven hundred fifty-one thousand, two hundred sixteen".