20120280 has 64 divisors (see below), whose sum is σ = 60963840. Its totient is φ = 5311872.

The previous prime is 20120263. The next prime is 20120281. The reversal of 20120280 is 8202102.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20120281) 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, 12057 + ... + 13623.

It is an arithmetic number, because the mean of its divisors is an integer number (952560).

Almost surely, 2^20120280 is an apocalyptic number.

20120280 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 20120280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30481920).

20120280 is an abundant number, since it is smaller than the sum of its proper divisors (40843560).

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

20120280 is a wasteful number, since it uses less digits than its factorization.

20120280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1688 (or 1684 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 20120280 is about 4485.5635097499. The cubic root of 20120280 is about 271.9848247012.

Adding to 20120280 its reverse (8202102), we get a palindrome (28322382).

The spelling of 20120280 in words is "twenty million, one hundred twenty thousand, two hundred eighty".