20561120 has 48 divisors (see below), whose sum is σ = 49070448. Its totient is φ = 8140800.

The previous prime is 20561117. The next prime is 20561147. The reversal of 20561120 is 2116502.

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, 16520 + ... + 17720.

It is an arithmetic number, because the mean of its divisors is an integer number (1022301).

Almost surely, 2^20561120 is an apocalyptic number.

20561120 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 20561120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24535224).

20561120 is an abundant number, since it is smaller than the sum of its proper divisors (28509328).

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

20561120 is a wasteful number, since it uses less digits than its factorization.

20561120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323 (or 1315 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 20561120 is about 4534.4371205255. The cubic root of 20561120 is about 273.9569079941.

Adding to 20561120 its reverse (2116502), we get a palindrome (22677622).

The spelling of 20561120 in words is "twenty million, five hundred sixty-one thousand, one hundred twenty".