21121045203 has 16 divisors (see below), whose sum is σ = 28667669760. Its totient is φ = 13828041696.

The previous prime is 21121045193. The next prime is 21121045217. The reversal of 21121045203 is 30254012112.

It is not a de Polignac number, because 21121045203 - 2²⁸ = 20852609747 is a prime.

It is a super-2 number, since 2×21121045203² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121045203.

It is not an unprimeable number, because it can be changed into a prime (21121045103) 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 15 ways as a sum of consecutive naturals, for example, 116626 + ... + 236312.

It is an arithmetic number, because the mean of its divisors is an integer number (1791729360).

Almost surely, 2^21121045203 is an apocalyptic number.

21121045203 is a deficient number, since it is larger than the sum of its proper divisors (7546624557).

21121045203 is a wasteful number, since it uses less digits than its factorization.

21121045203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120746.

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21121045203 its reverse (30254012112), we get a palindrome (51375057315).

The spelling of 21121045203 in words is "twenty-one billion, one hundred twenty-one million, forty-five thousand, two hundred three".