21213012223221 has 64 divisors (see below), whose sum is σ = 34881586790400. Its totient is φ = 11166631176960.

The previous prime is 21213012223199. The next prime is 21213012223237. The reversal of 21213012223221 is 12232221031212.

It is not a de Polignac number, because 21213012223221 - 2¹⁵ = 21213012190453 is a prime.

It is a super-2 number, since 2×21213012223221² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21213012223191 and 21213012223200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213012223261) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1270003756 + ... + 1270020458.

It is an arithmetic number, because the mean of its divisors is an integer number (545024793600).

Almost surely, 2^{21213012223221} is an apocalyptic number.

21213012223221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21213012223221 is a deficient number, since it is larger than the sum of its proper divisors (13668574567179).

21213012223221 is a wasteful number, since it uses less digits than its factorization.

21213012223221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25866.

The product of its (nonzero) digits is 1152, while the sum is 24.

Adding to 21213012223221 its reverse (12232221031212), we get a palindrome (33445233254433).

The spelling of 21213012223221 in words is "twenty-one trillion, two hundred thirteen billion, twelve million, two hundred twenty-three thousand, two hundred twenty-one".