21212222210212 has 36 divisors (see below), whose sum is σ = 40805740222380. Its totient is φ = 9641235957760.

The previous prime is 21212222210189. The next prime is 21212222210251. The reversal of 21212222210212 is 21201222221212.

It can be written as a sum of positive squares in 2 ways, for example, as 19379945934756 + 1832276275456 = 4402266^2 + 1353616^2 .

It is a super-2 number, since 2×21212222210212² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5315964 + ... + 8407372.

It is an arithmetic number, because the mean of its divisors is an integer number (1133492783955).

Almost surely, 2^{21212222210212} is an apocalyptic number.

21212222210212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21212222210212 is a deficient number, since it is larger than the sum of its proper divisors (19593518012168).

21212222210212 is a wasteful number, since it uses less digits than its factorization.

21212222210212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3105612 (or 3105599 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 21212222210212 its reverse (21201222221212), we get a palindrome (42413444431424).

The spelling of 21212222210212 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty-two million, two hundred ten thousand, two hundred twelve".