20557000 has 64 divisors (see below), whose sum is σ = 49037040. Its totient is φ = 8064000.

The previous prime is 20556979. The next prime is 20557003. The reversal of 20557000 is 75502.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1179396 + 19377604 = 1086^2 + 4402^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20557003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60832 + ... + 61168.

Almost surely, 2^20557000 is an apocalyptic number.

20557000 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 20557000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24518520).

20557000 is an abundant number, since it is smaller than the sum of its proper divisors (28480040).

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

20557000 is a wasteful number, since it uses less digits than its factorization.

20557000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419 (or 405 counting only the distinct ones).

The product of its (nonzero) digits is 350, while the sum is 19.

The square root of 20557000 is about 4533.9827966149. The cubic root of 20557000 is about 273.9386084420.

The spelling of 20557000 in words is "twenty million, five hundred fifty-seven thousand".