Search a number
-
+
20516864 = 2125009
BaseRepresentation
bin100111001000…
…1000000000000
31102121100211212
41032101000000
520223014424
62011425252
7336250634
oct116210000
942540755
1020516864
1110643695
126a55228
134334774
142a20dc4
151c0410e
hex1391000

20516864 has 26 divisors (see below), whose sum is σ = 41036910. Its totient is φ = 10256384.

The previous prime is 20516861. The next prime is 20516887. The reversal of 20516864 is 46861502.

It can be written as a sum of positive squares in only one way, i.e., 17305600 + 3211264 = 4160^2 + 1792^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 20516864.

It is not an unprimeable number, because it can be changed into a prime (20516861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1592 + ... + 6600.

Almost surely, 220516864 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 20516864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20518455).

20516864 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20516864 is an frugal number, since it uses more digits than its factorization.

20516864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5033 (or 5011 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 20516864 is about 4529.5545034804. The cubic root of 20516864 is about 273.7602107629.

The spelling of 20516864 in words is "twenty million, five hundred sixteen thousand, eight hundred sixty-four".

Divisors: 1 2 4 8 16 32 64 128 256 512 1024 2048 4096 5009 10018 20036 40072 80144 160288 320576 641152 1282304 2564608 5129216 10258432 20516864