21213031212 has 36 divisors (see below), whose sum is σ = 54152747376. Its totient is φ = 7000999200.

The previous prime is 21213031181. The next prime is 21213031219.

21213031212 is a `hidden beast` number, since 212 + 130 + 312 + 12 = 666.

21213031212 is nontrivially palindromic in base 10.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21213031219) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2913448 + ... + 2920719.

Almost surely, 2^21213031212 is an apocalyptic number.

It is an amenable number.

21213031212 is an abundant number, since it is smaller than the sum of its proper divisors (32939716164).

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

21213031212 is a wasteful number, since it uses less digits than its factorization.

21213031212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5834278 (or 5834273 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

It can be divided in two parts, 212130 and 31212, that added together give a palindrome (243342).

The spelling of 21213031212 in words is "twenty-one billion, two hundred thirteen million, thirty-one thousand, two hundred twelve".