20611220 has 96 divisors (see below), whose sum is σ = 53319168. Its totient is φ = 6538752.

The previous prime is 20611193. The next prime is 20611231. The reversal of 20611220 is 2211602.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 20611195 and 20611204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 119054 + ... + 119226.

It is an arithmetic number, because the mean of its divisors is an integer number (555408).

Almost surely, 2^20611220 is an apocalyptic number.

20611220 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 20611220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26659584).

20611220 is an abundant number, since it is smaller than the sum of its proper divisors (32707948).

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

20611220 is a wasteful number, since it uses less digits than its factorization.

20611220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 20611220 is about 4539.9581495868. The cubic root of 20611220 is about 274.1792387547.

Adding to 20611220 its reverse (2211602), we get a palindrome (22822822).

The spelling of 20611220 in words is "twenty million, six hundred eleven thousand, two hundred twenty".