20491685676 has 144 divisors (see below), whose sum is σ = 65052449280. Its totient is φ = 5283567360.

The previous prime is 20491685659. The next prime is 20491685681. The reversal of 20491685676 is 67658619402.

20491685676 is a `hidden beast` number, since 2 + 0 + 491 + 6 + 85 + 6 + 76 = 666.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 352785 + ... + 406743.

It is an arithmetic number, because the mean of its divisors is an integer number (451753120).

Almost surely, 2^20491685676 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20491685676, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32526224640).

20491685676 is an abundant number, since it is smaller than the sum of its proper divisors (44560763604).

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

20491685676 is a wasteful number, since it uses less digits than its factorization.

20491685676 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54124 (or 54119 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 20491685676 in words is "twenty billion, four hundred ninety-one million, six hundred eighty-five thousand, six hundred seventy-six".