20281856 has 40 divisors (see below), whose sum is σ = 46321440. Its totient is φ = 8690688.

The previous prime is 20281847. The next prime is 20281861. The reversal of 20281856 is 65818202.

It is a super-2 number, since 2×20281856² = 822707365609472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 755 + ... + 6413.

It is an arithmetic number, because the mean of its divisors is an integer number (1158036).

Almost surely, 2^20281856 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 20281856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23160720).

20281856 is an abundant number, since it is smaller than the sum of its proper divisors (26039584).

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

20281856 is an frugal number, since it uses more digits than its factorization.

20281856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5684 (or 5668 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 20281856 is about 4503.5381645990. The cubic root of 20281856 is about 272.7109429145.

The spelling of 20281856 in words is "twenty million, two hundred eighty-one thousand, eight hundred fifty-six".