21212213503 has 8 divisors (see below), whose sum is σ = 22845147696. Its totient is φ = 19579454400.

The previous prime is 21212213489. The next prime is 21212213509. The reversal of 21212213503 is 30531221212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21212213503 - 2⁹ = 21212212991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212213509) 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 7 ways as a sum of consecutive naturals, for example, 319668 + ... + 380278.

It is an arithmetic number, because the mean of its divisors is an integer number (2855643462).

Almost surely, 2^21212213503 is an apocalyptic number.

21212213503 is a deficient number, since it is larger than the sum of its proper divisors (1632934193).

21212213503 is a wasteful number, since it uses less digits than its factorization.

21212213503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87545.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 21212213503 its reverse (30531221212), we get a palindrome (51743434715).

It can be divided in two parts, 212122 and 13503, that added together give a square (225625 = 475²).

The spelling of 21212213503 in words is "twenty-one billion, two hundred twelve million, two hundred thirteen thousand, five hundred three".