21355355555103 has 4 divisors (see below), whose sum is σ = 28473807406808. Its totient is φ = 14236903703400.

The previous prime is 21355355555059. The next prime is 21355355555113. The reversal of 21355355555103 is 30155555355312.

It is a happy number.

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

It is not a de Polignac number, because 21355355555103 - 2⁹ = 21355355554591 is a prime.

It is a super-2 number, since 2×21355355555103² (a number of 27 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 (21355355555113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3559225925848 + ... + 3559225925853.

It is an arithmetic number, because the mean of its divisors is an integer number (7118451851702).

Almost surely, 2^{21355355555103} is an apocalyptic number.

21355355555103 is a deficient number, since it is larger than the sum of its proper divisors (7118451851705).

21355355555103 is an equidigital number, since it uses as much as digits as its factorization.

21355355555103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7118451851704.

The product of its (nonzero) digits is 4218750, while the sum is 48.

The spelling of 21355355555103 in words is "twenty-one trillion, three hundred fifty-five billion, three hundred fifty-five million, five hundred fifty-five thousand, one hundred three".