21011121003 has 16 divisors (see below), whose sum is σ = 29029214720. Its totient is φ = 13508468064.

The previous prime is 21011120993. The next prime is 21011121011. The reversal of 21011121003 is 30012111012.

It is not a de Polignac number, because 21011121003 - 2⁶ = 21011120939 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 21011121003.

It is not an unprimeable number, because it can be changed into a prime (21011121013) 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, 1020676 + ... + 1041057.

It is an arithmetic number, because the mean of its divisors is an integer number (1814325920).

Almost surely, 2^21011121003 is an apocalyptic number.

21011121003 is a deficient number, since it is larger than the sum of its proper divisors (8018093717).

21011121003 is a wasteful number, since it uses less digits than its factorization.

21011121003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2061858.

The product of its (nonzero) digits is 12, while the sum is 12.

Adding to 21011121003 its reverse (30012111012), we get a palindrome (51023232015).

Subtracting 21011121003 from its reverse (30012111012), we obtain a palindrome (9000990009).

The spelling of 21011121003 in words is "twenty-one billion, eleven million, one hundred twenty-one thousand, three".