20722153 has 4 divisors (see below), whose sum is σ = 21436740. Its totient is φ = 20007568.

The previous prime is 20722129. The next prime is 20722171. The reversal of 20722153 is 35122702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3640464 + 17081689 = 1908^2 + 4133^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20722153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20722123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 357250 + ... + 357307.

It is an arithmetic number, because the mean of its divisors is an integer number (5359185).

Almost surely, 2^20722153 is an apocalyptic number.

It is an amenable number.

20722153 is a deficient number, since it is larger than the sum of its proper divisors (714587).

20722153 is an equidigital number, since it uses as much as digits as its factorization.

20722153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 714586.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 20722153 is about 4552.1591580260. The cubic root of 20722153 is about 274.6702515936.

Adding to 20722153 its reverse (35122702), we get a palindrome (55844855).

It can be divided in two parts, 2072 and 2153, that added together give a square (4225 = 65²).

The spelling of 20722153 in words is "twenty million, seven hundred twenty-two thousand, one hundred fifty-three".