20491371936 has 216 divisors, whose sum is σ = 67931607744. Its totient is φ = 5842126080.

The previous prime is 20491371913. The next prime is 20491371937. The reversal of 20491371936 is 63917319402.

20491371936 is a `hidden beast` number, since 2 + 0 + 491 + 3 + 71 + 93 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 20491371891 and 20491371900.

It is not an unprimeable number, because it can be changed into a prime (20491371937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 8056681 + ... + 8059223.

It is an arithmetic number, because the mean of its divisors is an integer number (314498184).

Almost surely, 2^20491371936 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 20491371936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33965803872).

20491371936 is an abundant number, since it is smaller than the sum of its proper divisors (47440235808).

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

20491371936 is a wasteful number, since it uses less digits than its factorization.

20491371936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3144 (or 3126 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The spelling of 20491371936 in words is "twenty billion, four hundred ninety-one million, three hundred seventy-one thousand, nine hundred thirty-six".