21201212102 has 64 divisors (see below), whose sum is σ = 37920960000. Its totient is φ = 8883546336.

The previous prime is 21201212051. The next prime is 21201212143. The reversal of 21201212102 is 20121210212.

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

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 7972049 + ... + 7974707.

It is an arithmetic number, because the mean of its divisors is an integer number (592515000).

Almost surely, 2^21201212102 is an apocalyptic number.

21201212102 is a deficient number, since it is larger than the sum of its proper divisors (16719747898).

21201212102 is a wasteful number, since it uses less digits than its factorization.

21201212102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2938 (or 2924 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21201212102 its reverse (20121210212), we get a palindrome (41322422314).

The spelling of 21201212102 in words is "twenty-one billion, two hundred one million, two hundred twelve thousand, one hundred two".