20959131636 has 18 divisors (see below), whose sum is σ = 52980027282. Its totient is φ = 6986377200.

The previous prime is 20959131631. The next prime is 20959131671. The reversal of 20959131636 is 63613195902.

20959131636 is a `hidden beast` number, since 2 + 0 + 9 + 5 + 9 + 1 + 3 + 1 + 636 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20864069136 + 95062500 = 144444^2 + 9750^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20959131591 and 20959131600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20959131631) 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 5 ways as a sum of consecutive naturals, for example, 291099015 + ... + 291099086.

It is an arithmetic number, because the mean of its divisors is an integer number (2943334849).

Almost surely, 2^20959131636 is an apocalyptic number.

It is an amenable number.

20959131636 is an abundant number, since it is smaller than the sum of its proper divisors (32020895646).

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

20959131636 is a wasteful number, since it uses less digits than its factorization.

20959131636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 582198111 (or 582198106 counting only the distinct ones).

The product of its (nonzero) digits is 262440, while the sum is 45.

The spelling of 20959131636 in words is "twenty billion, nine hundred fifty-nine million, one hundred thirty-one thousand, six hundred thirty-six".