20116640 has 48 divisors (see below), whose sum is σ = 48353760. Its totient is φ = 7906560.

The previous prime is 20116637. The next prime is 20116667. The reversal of 20116640 is 4661102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8375 + ... + 10505.

It is an arithmetic number, because the mean of its divisors is an integer number (1007370).

Almost surely, 2^20116640 is an apocalyptic number.

20116640 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 20116640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24176880).

20116640 is an abundant number, since it is smaller than the sum of its proper divisors (28237120).

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

20116640 is a wasteful number, since it uses less digits than its factorization.

20116640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2205 (or 2197 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 20116640 is about 4485.1577452750. The cubic root of 20116640 is about 271.9684219396.

Adding to 20116640 its reverse (4661102), we get a palindrome (24777742).

The spelling of 20116640 in words is "twenty million, one hundred sixteen thousand, six hundred forty".