20761686 has 96 divisors (see below), whose sum is σ = 52835328. Its totient is φ = 5829120.

The previous prime is 20761669. The next prime is 20761693. The reversal of 20761686 is 68616702.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20761686.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 213990 + ... + 214086.

It is an arithmetic number, because the mean of its divisors is an integer number (550368).

Almost surely, 2^20761686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20761686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26417664).

20761686 is an abundant number, since it is smaller than the sum of its proper divisors (32073642).

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

20761686 is a wasteful number, since it uses less digits than its factorization.

20761686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 20761686 is about 4556.4993141665. The cubic root of 20761686 is about 274.8448094076.

It can be divided in two parts, 207616 and 86, that added together give a palindrome (207702).

The spelling of 20761686 in words is "twenty million, seven hundred sixty-one thousand, six hundred eighty-six".