21102203121 has 16 divisors (see below), whose sum is σ = 28827653568. Its totient is φ = 13722566400.

The previous prime is 21102203119. The next prime is 21102203123. The reversal of 21102203121 is 12130220112.

It is an interprime number because it is at equal distance from previous prime (21102203119) and next prime (21102203123).

It is not a de Polignac number, because 21102203121 - 2¹ = 21102203119 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21102203121.

It is not an unprimeable number, because it can be changed into a prime (21102203123) 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, 900726 + ... + 923856.

It is an arithmetic number, because the mean of its divisors is an integer number (1801728348).

Almost surely, 2^21102203121 is an apocalyptic number.

It is an amenable number.

21102203121 is a deficient number, since it is larger than the sum of its proper divisors (7725450447).

21102203121 is a wasteful number, since it uses less digits than its factorization.

21102203121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30592.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21102203121 its reverse (12130220112), we get a palindrome (33232423233).

The spelling of 21102203121 in words is "twenty-one billion, one hundred two million, two hundred three thousand, one hundred twenty-one".