20722 has 8 divisors (see below), whose sum is σ = 33516.
Its totient is φ = 9552.
The previous prime is 20719. The next prime is 20731. The reversal of 20722 is 22702.
It can be written as a sum of positive squares in 2 ways, for example, as 19881 + 841 = 141^2 + 29^2
It is a sphenic number, since it is the product of 3 distinct primes.
It is a Harshad number since it is a multiple of its sum of digits (13).
It is a nialpdrome in base 12.
It is a zygodrome in base 12.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 373 + ... + 424.
220722 is an apocalyptic number.
20722 is a deficient number, since it is larger than the sum of its proper divisors (12794).
20722 is a wasteful number, since it uses less digits than its factorization.
20722 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 812.
The product of its (nonzero) digits is 56, while the sum is 13.
The square root of 20722 is about 143.9513806811.
The cubic root of 20722 is about 27.4669575592.
It can be divided in two parts, 207 and 22, that multiplied together give a palindrome (4554).
The spelling of 20722 in words is "twenty thousand, seven hundred twenty-two", and thus it is an iban number.