20145280 has 32 divisors (see below), whose sum is σ = 48161340. Its totient is φ = 8057856.

The previous prime is 20145277. The next prime is 20145313. The reversal of 20145280 is 8254102.

It can be written as a sum of positive squares in 2 ways, for example, as 20142144 + 3136 = 4488^2 + 56^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15099 + ... + 16378.

Almost surely, 2^20145280 is an apocalyptic number.

20145280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20145280 is an abundant number, since it is smaller than the sum of its proper divisors (28016060).

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

20145280 is an equidigital number, since it uses as much as digits as its factorization.

20145280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31496 (or 31484 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 20145280 is about 4488.3493625162. The cubic root of 20145280 is about 272.0974276127.

Adding to 20145280 its reverse (8254102), we get a palindrome (28399382).

The spelling of 20145280 in words is "twenty million, one hundred forty-five thousand, two hundred eighty".