21121240303 has 4 divisors (see below), whose sum is σ = 21308154048. Its totient is φ = 20934326560.

The previous prime is 21121240297. The next prime is 21121240381. The reversal of 21121240303 is 30304212112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21121240303 - 2⁹ = 21121239791 is a prime.

It is a super-2 number, since 2×21121240303² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121240003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93456703 + ... + 93456928.

It is an arithmetic number, because the mean of its divisors is an integer number (5327038512).

Almost surely, 2^21121240303 is an apocalyptic number.

21121240303 is a deficient number, since it is larger than the sum of its proper divisors (186913745).

21121240303 is a wasteful number, since it uses less digits than its factorization.

21121240303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186913744.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21121240303 its reverse (30304212112), we get a palindrome (51425452415).

The spelling of 21121240303 in words is "twenty-one billion, one hundred twenty-one million, two hundred forty thousand, three hundred three".