21121210211212 has 48 divisors (see below), whose sum is σ = 39818452875264. Its totient is φ = 9774338112000.

The previous prime is 21121210211161. The next prime is 21121210211219. The reversal of 21121210211212 is 21211201212112.

It is a happy number.

It is a super-2 number, since 2×21121210211212² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121210211212.

It is not an unprimeable number, because it can be changed into a prime (21121210211219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21890287 + ... + 22834777.

It is an arithmetic number, because the mean of its divisors is an integer number (829551101568).

Almost surely, 2^{21121210211212} is an apocalyptic number.

It is an amenable number.

21121210211212 is a deficient number, since it is larger than the sum of its proper divisors (18697242664052).

21121210211212 is a wasteful number, since it uses less digits than its factorization.

21121210211212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 952390 (or 952388 counting only the distinct ones).

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

Adding to 21121210211212 its reverse (21211201212112), we get a palindrome (42332411423324).

The spelling of 21121210211212 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred ten million, two hundred eleven thousand, two hundred twelve".