20722231 has 4 divisors (see below), whose sum is σ = 20731464. Its totient is φ = 20713000.

The previous prime is 20722199. The next prime is 20722237. The reversal of 20722231 is 13222702.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20722231 - 2⁵ = 20722199 is a prime.

It is a super-2 number, since 2×20722231² = 858821715234722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20722199 and 20722208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20722237) 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, 1161 + ... + 6541.

It is an arithmetic number, because the mean of its divisors is an integer number (5182866).

Almost surely, 2^20722231 is an apocalyptic number.

20722231 is a deficient number, since it is larger than the sum of its proper divisors (9233).

20722231 is an equidigital number, since it uses as much as digits as its factorization.

20722231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9232.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 20722231 is about 4552.1677253810. The cubic root of 20722231 is about 274.6705962208.

Adding to 20722231 its reverse (13222702), we get a palindrome (33944933).

The spelling of 20722231 in words is "twenty million, seven hundred twenty-two thousand, two hundred thirty-one".