21221185722 has 16 divisors (see below), whose sum is σ = 46300768992. Its totient is φ = 6430662320.

The previous prime is 21221185717. The next prime is 21221185723. The reversal of 21221185722 is 22758112212.

21221185722 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×21221185722² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21221185723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 160766493 + ... + 160766624.

It is an arithmetic number, because the mean of its divisors is an integer number (2893798062).

Almost surely, 2^21221185722 is an apocalyptic number.

21221185722 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21221185722 is an abundant number, since it is smaller than the sum of its proper divisors (25079583270).

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

21221185722 is a wasteful number, since it uses less digits than its factorization.

21221185722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321533133.

The product of its digits is 8960, while the sum is 33.

Adding to 21221185722 its reverse (22758112212), we get a palindrome (43979297934).

The spelling of 21221185722 in words is "twenty-one billion, two hundred twenty-one million, one hundred eighty-five thousand, seven hundred twenty-two".