20557140 has 48 divisors (see below), whose sum is σ = 57966720. Its totient is φ = 5443200.

The previous prime is 20557129. The next prime is 20557153. The reversal of 20557140 is 4175502.

It is a self number, because there is not a number n which added to its sum of digits gives 20557140.

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 15 ways as a sum of consecutive naturals, for example, 7926 + ... + 10194.

It is an arithmetic number, because the mean of its divisors is an integer number (1207640).

Almost surely, 2^20557140 is an apocalyptic number.

20557140 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 20557140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28983360).

20557140 is an abundant number, since it is smaller than the sum of its proper divisors (37409580).

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

20557140 is a wasteful number, since it uses less digits than its factorization.

20557140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2432 (or 2430 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 20557140 is about 4533.9982355533. The cubic root of 20557140 is about 273.9392303116.

The spelling of 20557140 in words is "twenty million, five hundred fifty-seven thousand, one hundred forty".