21010131212 has 72 divisors (see below), whose sum is σ = 43461250560. Its totient is φ = 8859745440.

The previous prime is 21010131203. The next prime is 21010131313. The reversal of 21010131212 is 21213101012.

It is a super-2 number, since 2×21010131212² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4813343 + ... + 4817705.

It is an arithmetic number, because the mean of its divisors is an integer number (603628480).

Almost surely, 2^21010131212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21010131212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21730625280).

21010131212 is an abundant number, since it is smaller than the sum of its proper divisors (22451119348).

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

21010131212 is a wasteful number, since it uses less digits than its factorization.

21010131212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4771 (or 4762 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21010131212 its reverse (21213101012), we get a palindrome (42223232224).

The spelling of 21010131212 in words is "twenty-one billion, ten million, one hundred thirty-one thousand, two hundred twelve".