20404220 has 24 divisors (see below), whose sum is σ = 44712864. Its totient is φ = 7806656.

The previous prime is 20404213. The next prime is 20404249. The reversal of 20404220 is 2240402.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20404195 and 20404204.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21719 + ... + 22638.

It is an arithmetic number, because the mean of its divisors is an integer number (1863036).

Almost surely, 2^20404220 is an apocalyptic number.

20404220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20404220 is an abundant number, since it is smaller than the sum of its proper divisors (24308644).

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

20404220 is a wasteful number, since it uses less digits than its factorization.

20404220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44389 (or 44387 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

The square root of 20404220 is about 4517.1030539495. The cubic root of 20404220 is about 273.2582813307.

Adding to 20404220 its reverse (2240402), we get a palindrome (22644622).

The spelling of 20404220 in words is "twenty million, four hundred four thousand, two hundred twenty".