20117680 has 40 divisors (see below), whose sum is σ = 51027984. Its totient is φ = 7315200.

The previous prime is 20117627. The next prime is 20117693. The reversal of 20117680 is 8671102.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10551 + ... + 12310.

Almost surely, 2^20117680 is an apocalyptic number.

20117680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20117680 is an abundant number, since it is smaller than the sum of its proper divisors (30910304).

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

20117680 is a wasteful number, since it uses less digits than its factorization.

20117680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22885 (or 22879 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 20117680 is about 4485.2736817278. The cubic root of 20117680 is about 271.9731086448.

Adding to 20117680 its reverse (8671102), we get a palindrome (28788782).

The spelling of 20117680 in words is "twenty million, one hundred seventeen thousand, six hundred eighty".