20558220 has 96 divisors (see below), whose sum is σ = 60371136. Its totient is φ = 5222400.

The previous prime is 20558207. The next prime is 20558221. The reversal of 20558220 is 2285502.

It is not an unprimeable number, because it can be changed into a prime (20558221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 149992 + ... + 150128.

It is an arithmetic number, because the mean of its divisors is an integer number (628866).

Almost surely, 2^20558220 is an apocalyptic number.

20558220 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 20558220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30185568).

20558220 is an abundant number, since it is smaller than the sum of its proper divisors (39812916).

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

20558220 is a wasteful number, since it uses less digits than its factorization.

20558220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 20558220 is about 4534.1173341677. The cubic root of 20558220 is about 273.9440274962.

It can be divided in two parts, 2055 and 8220, that multiplied together give a square (16892100 = 4110²).

The spelling of 20558220 in words is "twenty million, five hundred fifty-eight thousand, two hundred twenty".