21012212121112 has 16 divisors (see below), whose sum is σ = 39766102380360. Its totient is φ = 10407918153024.

The previous prime is 21012212121073. The next prime is 21012212121113. The reversal of 21012212121112 is 21112121221012.

It is a happy number.

It is a super-2 number, since 2×21012212121112² (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 21012212121112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012212121113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12273487533 + ... + 12273489244.

Almost surely, 2^{21012212121112} is an apocalyptic number.

It is an amenable number.

21012212121112 is a deficient number, since it is larger than the sum of its proper divisors (18753890259248).

21012212121112 is a wasteful number, since it uses less digits than its factorization.

21012212121112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24546976890 (or 24546976886 counting only the distinct ones).

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

Adding to 21012212121112 its reverse (21112121221012), we get a palindrome (42124333342124).

The spelling of 21012212121112 in words is "twenty-one trillion, twelve billion, two hundred twelve million, one hundred twenty-one thousand, one hundred twelve".