21106550203 has 2 divisors, whose sum is σ = 21106550204. Its totient is φ = 21106550202.

The previous prime is 21106550177. The next prime is 21106550207. The reversal of 21106550203 is 30205560112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21106550203 - 2⁹ = 21106549691 is a prime.

It is a super-2 number, since 2×21106550203² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21106550207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10553275101 + 10553275102.

It is an arithmetic number, because the mean of its divisors is an integer number (10553275102).

Almost surely, 2^21106550203 is an apocalyptic number.

21106550203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21106550203 is an equidigital number, since it uses as much as digits as its factorization.

21106550203 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 25.

Subtracting 21106550203 from its reverse (30205560112), we obtain a palindrome (9099009909).

The spelling of 21106550203 in words is "twenty-one billion, one hundred six million, five hundred fifty thousand, two hundred three".