21121012212 has 24 divisors (see below), whose sum is σ = 49284720576. Its totient is φ = 7040000448.

The previous prime is 21121012207. The next prime is 21121012219. The reversal of 21121012212 is 21221012112.

It is a junction number, because it is equal to n+sod(n) for n = 21121012191 and 21121012200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121012219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 437593 + ... + 483455.

It is an arithmetic number, because the mean of its divisors is an integer number (2053530024).

Almost surely, 2^21121012212 is an apocalyptic number.

It is an amenable number.

21121012212 is an abundant number, since it is smaller than the sum of its proper divisors (28163708364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21121012212 is a wasteful number, since it uses less digits than its factorization.

21121012212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84247 (or 84245 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21121012212 its reverse (21221012112), we get a palindrome (42342024324).

The spelling of 21121012212 in words is "twenty-one billion, one hundred twenty-one million, twelve thousand, two hundred twelve".