20439220 has 12 divisors (see below), whose sum is σ = 42922404. Its totient is φ = 8175680.

The previous prime is 20439191. The next prime is 20439257. The reversal of 20439220 is 2293402.

It can be written as a sum of positive squares in 2 ways, for example, as 8076964 + 12362256 = 2842^2 + 3516^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20439191 and 20439200.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 510961 + ... + 511000.

It is an arithmetic number, because the mean of its divisors is an integer number (3576867).

Almost surely, 2^20439220 is an apocalyptic number.

20439220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20439220 is an abundant number, since it is smaller than the sum of its proper divisors (22483184).

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

20439220 is a wasteful number, since it uses less digits than its factorization.

20439220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1021970 (or 1021968 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 20439220 is about 4520.9755584387. The cubic root of 20439220 is about 273.4144349198.

The spelling of 20439220 in words is "twenty million, four hundred thirty-nine thousand, two hundred twenty".