21210111012 has 24 divisors (see below), whose sum is σ = 49520872800. Its totient is φ = 7065663616.

The previous prime is 21210110981. The next prime is 21210111019. The reversal of 21210111012 is 21011101212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (21210111019) 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, 526437 + ... + 565292.

It is an arithmetic number, because the mean of its divisors is an integer number (2063369700).

Almost surely, 2^21210111012 is an apocalyptic number.

It is an amenable number.

21210111012 is an abundant number, since it is smaller than the sum of its proper divisors (28310761788).

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

21210111012 is a wasteful number, since it uses less digits than its factorization.

21210111012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1093355 (or 1093353 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21210111012 its reverse (21011101212), we get a palindrome (42221212224).

The spelling of 21210111012 in words is "twenty-one billion, two hundred ten million, one hundred eleven thousand, twelve".