20557208 has 32 divisors (see below), whose sum is σ = 44716800. Its totient is φ = 8677152.

The previous prime is 20557181. The next prime is 20557211. The reversal of 20557208 is 80275502.

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 7 ways as a sum of consecutive naturals, for example, 1013 + ... + 6491.

It is an arithmetic number, because the mean of its divisors is an integer number (1397400).

Almost surely, 2^20557208 is an apocalyptic number.

20557208 is a gapful number since it is divisible by the number (28) 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 20557208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22358400).

20557208 is an abundant number, since it is smaller than the sum of its proper divisors (24159592).

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

20557208 is a wasteful number, since it uses less digits than its factorization.

20557208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5559 (or 5555 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 29.

The square root of 20557208 is about 4534.0057344472. The cubic root of 20557208 is about 273.9395323615.

The spelling of 20557208 in words is "twenty million, five hundred fifty-seven thousand, two hundred eight".