22321221 has 32 divisors (see below), whose sum is σ = 34328448. Its totient is φ = 12779520.

The previous prime is 22321217. The next prime is 22321231. The reversal of 22321221 is 12212322.

It is a happy number.

22321221 is a nontrivial binomial coefficient, being equal to C(6682, 2).

It is not a de Polignac number, because 22321221 - 2² = 22321217 is a prime.

It is a super-3 number, since 3×22321221³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 22321221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22321231) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 86725 + ... + 86981.

It is an arithmetic number, because the mean of its divisors is an integer number (1072764).

Almost surely, 2^22321221 is an apocalyptic number.

22321221 is the 6681-st triangular number and also the 3341-st hexagonal number.

It is an amenable number.

22321221 is a deficient number, since it is larger than the sum of its proper divisors (12007227).

22321221 is a wasteful number, since it uses less digits than its factorization.

22321221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421.

The product of its digits is 96, while the sum is 15.

The square root of 22321221 is about 4724.5339452691. The cubic root of 22321221 is about 281.5610973412.

Adding to 22321221 its reverse (12212322), we get a palindrome (34533543).

It can be divided in two parts, 2232 and 1221, that multiplied together give a palindrome (2725272).

The spelling of 22321221 in words is "twenty-two million, three hundred twenty-one thousand, two hundred twenty-one".