20117880 has 192 divisors, whose sum is σ = 70761600. Its totient is φ = 4945920.

The previous prime is 20117869. The next prime is 20117891. The reversal of 20117880 is 8871102.

It is an interprime number because it is at equal distance from previous prime (20117869) and next prime (20117891).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 428017 + ... + 428063.

It is an arithmetic number, because the mean of its divisors is an integer number (368550).

Almost surely, 2^20117880 is an apocalyptic number.

20117880 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 20117880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35380800).

20117880 is an abundant number, since it is smaller than the sum of its proper divisors (50643720).

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

20117880 is a wasteful number, since it uses less digits than its factorization.

20117880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 20117880 is about 4485.2959768559. The cubic root of 20117880 is about 271.9740099158.

Adding to 20117880 its reverse (8871102), we get a palindrome (28988982).

It can be divided in two parts, 201 and 17880, that added together give a palindrome (18081).

The spelling of 20117880 in words is "twenty million, one hundred seventeen thousand, eight hundred eighty".