20106720 has 72 divisors (see below), whose sum is σ = 68619096. Its totient is φ = 5361408.

The previous prime is 20106683. The next prime is 20106721. The reversal of 20106720 is 2760102.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20106693 and 20106702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20106721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5542 + ... + 8421.

It is an arithmetic number, because the mean of its divisors is an integer number (953043).

Almost surely, 2^20106720 is an apocalyptic number.

20106720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20106720 is an abundant number, since it is smaller than the sum of its proper divisors (48512376).

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

20106720 is a wasteful number, since it uses less digits than its factorization.

20106720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13984 (or 13973 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 20106720 is about 4484.0517392198. The cubic root of 20106720 is about 271.9237098615.

Adding to 20106720 its reverse (2760102), we get a palindrome (22866822).

The spelling of 20106720 in words is "twenty million, one hundred six thousand, seven hundred twenty".