21102609503 has 4 divisors (see below), whose sum is σ = 22020114288. Its totient is φ = 20185104720.

The previous prime is 21102609499. The next prime is 21102609511. The reversal of 21102609503 is 30590620112.

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 21102609503 - 2² = 21102609499 is a prime.

It is a super-2 number, since 2×21102609503² (a number of 21 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 (21102609533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 458752358 + ... + 458752403.

It is an arithmetic number, because the mean of its divisors is an integer number (5505028572).

Almost surely, 2^21102609503 is an apocalyptic number.

21102609503 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21102609503 is a deficient number, since it is larger than the sum of its proper divisors (917504785).

21102609503 is an equidigital number, since it uses as much as digits as its factorization.

21102609503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917504784.

The product of its (nonzero) digits is 3240, while the sum is 29.

The spelling of 21102609503 in words is "twenty-one billion, one hundred two million, six hundred nine thousand, five hundred three".