21203303225 has 48 divisors (see below), whose sum is σ = 29520735552. Its totient is φ = 15004604160.

The previous prime is 21203303221. The next prime is 21203303293. The reversal of 21203303225 is 52230330212.

It is not a de Polignac number, because 21203303225 - 2² = 21203303221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21203303225.

It is not an unprimeable number, because it can be changed into a prime (21203303221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 726362 + ... + 754988.

It is an arithmetic number, because the mean of its divisors is an integer number (615015324).

Almost surely, 2^21203303225 is an apocalyptic number.

21203303225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21203303225 is a deficient number, since it is larger than the sum of its proper divisors (8317432327).

21203303225 is a wasteful number, since it uses less digits than its factorization.

21203303225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28746 (or 28741 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 23.

Adding to 21203303225 its reverse (52230330212), we get a palindrome (73433633437).

The spelling of 21203303225 in words is "twenty-one billion, two hundred three million, three hundred three thousand, two hundred twenty-five".