21213240303 has 16 divisors (see below), whose sum is σ = 29348248160. Its totient is φ = 13618077696.

The previous prime is 21213240283. The next prime is 21213240313. The reversal of 21213240303 is 30304231212.

It is not a de Polignac number, because 21213240303 - 2⁹ = 21213239791 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21213240303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213240313) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 974338 + ... + 995871.

It is an arithmetic number, because the mean of its divisors is an integer number (1834265510).

Almost surely, 2^21213240303 is an apocalyptic number.

21213240303 is a deficient number, since it is larger than the sum of its proper divisors (8135007857).

21213240303 is a wasteful number, since it uses less digits than its factorization.

21213240303 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1970346.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21213240303 its reverse (30304231212), we get a palindrome (51517471515).

Subtracting 21213240303 from its reverse (30304231212), we obtain a palindrome (9090990909).

The spelling of 21213240303 in words is "twenty-one billion, two hundred thirteen million, two hundred forty thousand, three hundred three".