21011111222212 has 24 divisors (see below), whose sum is σ = 38038076377560. Its totient is φ = 10143103111680.

The previous prime is 21011111222117. The next prime is 21011111222291. The reversal of 21011111222212 is 21222211111012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2666114214976 + 18344997007236 = 1632824^2 + 4283106^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21011111222212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4539898 + ... + 7914094.

It is an arithmetic number, because the mean of its divisors is an integer number (1584919849065).

Almost surely, 2^{21011111222212} is an apocalyptic number.

It is an amenable number.

21011111222212 is a deficient number, since it is larger than the sum of its proper divisors (17026965155348).

21011111222212 is a wasteful number, since it uses less digits than its factorization.

21011111222212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3427911 (or 3427909 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21011111222212 its reverse (21222211111012), we get a palindrome (42233322333224).

The spelling of 21011111222212 in words is "twenty-one trillion, eleven billion, one hundred eleven million, two hundred twenty-two thousand, two hundred twelve".