21043212102 has 80 divisors (see below), whose sum is σ = 54464862672. Its totient is φ = 6001620480.

The previous prime is 21043212089. The next prime is 21043212103. The reversal of 21043212102 is 20121234012.

It is a happy number.

21043212102 is a `hidden beast` number, since 21 + 0 + 432 + 1 + 210 + 2 = 666.

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 (21043212103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 317023 + ... + 377610.

Almost surely, 2^21043212102 is an apocalyptic number.

21043212102 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21043212102 is an abundant number, since it is smaller than the sum of its proper divisors (33421650570).

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

21043212102 is a wasteful number, since it uses less digits than its factorization.

21043212102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 694675 (or 694666 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21043212102 its reverse (20121234012), we get a palindrome (41164446114).

The spelling of 21043212102 in words is "twenty-one billion, forty-three million, two hundred twelve thousand, one hundred two".