20557900 has 54 divisors (see below), whose sum is σ = 49063700. Its totient is φ = 7471200.

The previous prime is 20557891. The next prime is 20557907. The reversal of 20557900 is 975502.

It is not an unprimeable number, because it can be changed into a prime (20557907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 11251 + ... + 12949.

Almost surely, 2^20557900 is an apocalyptic number.

20557900 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 20557900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24531850).

20557900 is an abundant number, since it is smaller than the sum of its proper divisors (28505800).

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

20557900 is a wasteful number, since it uses less digits than its factorization.

20557900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1735 (or 1717 counting only the distinct ones).

The product of its (nonzero) digits is 3150, while the sum is 28.

The square root of 20557900 is about 4534.0820460155. The cubic root of 20557900 is about 273.9426061257.

The spelling of 20557900 in words is "twenty million, five hundred fifty-seven thousand, nine hundred".