20722237 has 2 divisors, whose sum is σ = 20722238. Its totient is φ = 20722236.

The previous prime is 20722199. The next prime is 20722277. The reversal of 20722237 is 73222702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20602521 + 119716 = 4539^2 + 346^2 .

It is a cyclic number.

It is not a de Polignac number, because 20722237 - 2¹⁵ = 20689469 is a prime.

It is a super-2 number, since 2×20722237² = 858822212568338, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20722277) 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 as a sum of consecutive naturals, namely, 10361118 + 10361119.

It is an arithmetic number, because the mean of its divisors is an integer number (10361119).

Almost surely, 2^20722237 is an apocalyptic number.

It is an amenable number.

20722237 is a deficient number, since it is larger than the sum of its proper divisors (1).

20722237 is an equidigital number, since it uses as much as digits as its factorization.

20722237 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2352, while the sum is 25.

The square root of 20722237 is about 4552.1683844076. The cubic root of 20722237 is about 274.6706227305.

Adding to 20722237 its reverse (73222702), we get a palindrome (93944939).

The spelling of 20722237 in words is "twenty million, seven hundred twenty-two thousand, two hundred thirty-seven".