21012220103 has 4 divisors (see below), whose sum is σ = 24013965840. Its totient is φ = 18010474368.

The previous prime is 21012220037. The next prime is 21012220109. The reversal of 21012220103 is 30102221012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21012220103 - 2²⁴ = 20995442887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012220109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1500872858 + ... + 1500872871.

It is an arithmetic number, because the mean of its divisors is an integer number (6003491460).

Almost surely, 2^21012220103 is an apocalyptic number.

21012220103 is a deficient number, since it is larger than the sum of its proper divisors (3001745737).

21012220103 is an equidigital number, since it uses as much as digits as its factorization.

21012220103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3001745736.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21012220103 its reverse (30102221012), we get a palindrome (51114441115).

Subtracting 21012220103 from its reverse (30102221012), we obtain a palindrome (9090000909).

The spelling of 21012220103 in words is "twenty-one billion, twelve million, two hundred twenty thousand, one hundred three".