20521056 has 48 divisors (see below), whose sum is σ = 54211248. Its totient is φ = 6796800.

The previous prime is 20521049. The next prime is 20521063. The reversal of 20521056 is 65012502.

It is an interprime number because it is at equal distance from previous prime (20521049) and next prime (20521063).

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×20521056² = 842227478710272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16786 + ... + 17966.

It is an arithmetic number, because the mean of its divisors is an integer number (1129401).

Almost surely, 2^20521056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20521056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27105624).

20521056 is an abundant number, since it is smaller than the sum of its proper divisors (33690192).

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

20521056 is a wasteful number, since it uses less digits than its factorization.

20521056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1375 (or 1367 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 20521056 is about 4530.0172185103. The cubic root of 20521056 is about 273.7788543635.

Adding to 20521056 its reverse (65012502), we get a palindrome (85533558).

The spelling of 20521056 in words is "twenty million, five hundred twenty-one thousand, fifty-six".