21204040212 has 36 divisors (see below), whose sum is σ = 54244881600. Its totient is φ = 6982855632.

The previous prime is 21204040189. The next prime is 21204040213.

21204040212 is a `hidden beast` number, since 212 + 0 + 40 + 402 + 12 = 666.

21204040212 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 super-2 number, since 2×21204040212² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204040213) 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, 3545212 + ... + 3551187.

Almost surely, 2^21204040212 is an apocalyptic number.

It is an amenable number.

21204040212 is an abundant number, since it is smaller than the sum of its proper divisors (33040841388).

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

21204040212 is a wasteful number, since it uses less digits than its factorization.

21204040212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7096492 (or 7096487 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

It can be divided in two parts, 212040 and 40212, that added together give a palindrome (252252).

The spelling of 21204040212 in words is "twenty-one billion, two hundred four million, forty thousand, two hundred twelve".