21211212203 has 16 divisors (see below), whose sum is σ = 22131273600. Its totient is φ = 20316341760.

The previous prime is 21211212173. The next prime is 21211212233. The reversal of 21211212203 is 30221211212.

It is an interprime number because it is at equal distance from previous prime (21211212173) and next prime (21211212233).

It is a cyclic number.

It is not a de Polignac number, because 21211212203 - 2¹⁶ = 21211146667 is a prime.

It is a super-2 number, since 2×21211212203² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21211212233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 344183 + ... + 401103.

It is an arithmetic number, because the mean of its divisors is an integer number (1383204600).

Almost surely, 2^21211212203 is an apocalyptic number.

21211212203 is a deficient number, since it is larger than the sum of its proper divisors (920061397).

21211212203 is an equidigital number, since it uses as much as digits as its factorization.

21211212203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57142.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21211212203 its reverse (30221211212), we get a palindrome (51432423415).

Subtracting 21211212203 from its reverse (30221211212), we obtain a palindrome (9009999009).

The spelling of 21211212203 in words is "twenty-one billion, two hundred eleven million, two hundred twelve thousand, two hundred three".