20111680 has 56 divisors (see below), whose sum is σ = 50721768. Its totient is φ = 7569408.

The previous prime is 20111621. The next prime is 20111681. The reversal of 20111680 is 8611102.

It can be written as a sum of positive squares in 4 ways, for example, as 1032256 + 19079424 = 1016^2 + 4368^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3592 + ... + 7288.

Almost surely, 2^20111680 is an apocalyptic number.

20111680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20111680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25360884).

20111680 is an abundant number, since it is smaller than the sum of its proper divisors (30610088).

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

20111680 is a wasteful number, since it uses less digits than its factorization.

20111680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3731 (or 3721 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 19.

The square root of 20111680 is about 4484.6047763432. The cubic root of 20111680 is about 271.9460677384.

Adding to 20111680 its reverse (8611102), we get a palindrome (28722782).

It can be divided in two parts, 201 and 11680, that added together give a square (11881 = 109²).

The spelling of 20111680 in words is "twenty million, one hundred eleven thousand, six hundred eighty".