20127720 has 64 divisors (see below), whose sum is σ = 61871040. Its totient is φ = 5235200.

The previous prime is 20127713. The next prime is 20127727. The reversal of 20127720 is 2772102.

It is an interprime number because it is at equal distance from previous prime (20127713) and next prime (20127727).

It is a super-2 number, since 2×20127720² = 810250224796800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20127727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2875 + ... + 6965.

It is an arithmetic number, because the mean of its divisors is an integer number (966735).

Almost surely, 2^20127720 is an apocalyptic number.

20127720 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 20127720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30935520).

20127720 is an abundant number, since it is smaller than the sum of its proper divisors (41743320).

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

20127720 is a wasteful number, since it uses less digits than its factorization.

20127720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4146 (or 4142 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 21.

The square root of 20127720 is about 4486.3927603365. The cubic root of 20127720 is about 272.0183450718.

Adding to 20127720 its reverse (2772102), we get a palindrome (22899822).

The spelling of 20127720 in words is "twenty million, one hundred twenty-seven thousand, seven hundred twenty".