20851360 has 60 divisors (see below), whose sum is σ = 51998058. Its totient is φ = 7901568.

The previous prime is 20851331. The next prime is 20851361. The reversal of 20851360 is 6315802.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18766224 + 2085136 = 4332^2 + 1444^2 .

It is not an unprimeable number, because it can be changed into a prime (20851361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1097431 + ... + 1097449.

Almost surely, 2^20851360 is an apocalyptic number.

20851360 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 20851360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25999029).

20851360 is an abundant number, since it is smaller than the sum of its proper divisors (31146698).

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

20851360 is an frugal number, since it uses more digits than its factorization.

20851360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 26 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 20851360 is about 4566.3289412831. The cubic root of 20851360 is about 275.2399448508.

Multiplying 20851360 by its product of nonzero digits (1440), we get a square (30025958400 = 173280²).

The spelling of 20851360 in words is "twenty million, eight hundred fifty-one thousand, three hundred sixty".