20011320 has 128 divisors (see below), whose sum is σ = 76262400. Its totient is φ = 4572288.

The previous prime is 20011319. The next prime is 20011349. The reversal of 20011320 is 2311002.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 6237 + ... + 8883.

It is an arithmetic number, because the mean of its divisors is an integer number (595800).

Almost surely, 2^20011320 is an apocalyptic number.

20011320 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 20011320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38131200).

20011320 is an abundant number, since it is smaller than the sum of its proper divisors (56251080).

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

20011320 is a wasteful number, since it uses less digits than its factorization.

20011320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2674 (or 2664 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 20011320 is about 4473.4013904411. The cubic root of 20011320 is about 271.4929640129.

Adding to 20011320 its reverse (2311002), we get a palindrome (22322322).

It can be divided in two parts, 2001 and 1320, that added together give a triangular number (3321 = T₈₁).

The spelling of 20011320 in words is "twenty million, eleven thousand, three hundred twenty".