20400222 has 16 divisors (see below), whose sum is σ = 41176080. Its totient is φ = 6737472.

The previous prime is 20400197. The next prime is 20400239. The reversal of 20400222 is 22200402.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20400198 and 20400207.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 14943 + ... + 16250.

It is an arithmetic number, because the mean of its divisors is an integer number (2573505).

Almost surely, 2^20400222 is an apocalyptic number.

20400222 is an abundant number, since it is smaller than the sum of its proper divisors (20775858).

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

20400222 is a wasteful number, since it uses less digits than its factorization.

20400222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31307.

The product of its (nonzero) digits is 64, while the sum is 12.

The square root of 20400222 is about 4516.6604920007. The cubic root of 20400222 is about 273.2404327685.

Adding to 20400222 its reverse (22200402), we get a palindrome (42600624).

The spelling of 20400222 in words is "twenty million, four hundred thousand, two hundred twenty-two".