20722280 has 16 divisors (see below), whose sum is σ = 46625220. Its totient is φ = 8288896.

The previous prime is 20722277. The next prime is 20722283. The reversal of 20722280 is 8222702.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20722277) and next prime (20722283).

It can be written as a sum of positive squares in 2 ways, for example, as 20268004 + 454276 = 4502^2 + 674^2 .

It is not an unprimeable number, because it can be changed into a prime (20722283) 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 3 ways as a sum of consecutive naturals, for example, 258989 + ... + 259068.

Almost surely, 2^20722280 is an apocalyptic number.

20722280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20722280 is an abundant number, since it is smaller than the sum of its proper divisors (25902940).

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

20722280 is a wasteful number, since it uses less digits than its factorization.

20722280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518068 (or 518064 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 20722280 is about 4552.1731074290. The cubic root of 20722280 is about 274.6708127169.

Adding to 20722280 its reverse (8222702), we get a palindrome (28944982).

The spelling of 20722280 in words is "twenty million, seven hundred twenty-two thousand, two hundred eighty".