21220324025 has 12 divisors (see below), whose sum is σ = 26333846892. Its totient is φ = 16962939840.

The previous prime is 21220324007. The next prime is 21220324033. The reversal of 21220324025 is 52042302212.

It can be written as a sum of positive squares in 6 ways, for example, as 326199721 + 20894124304 = 18061^2 + 144548^2 .

It is not a de Polignac number, because 21220324025 - 2²⁴ = 21203546809 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 300422 + ... + 364271.

It is an arithmetic number, because the mean of its divisors is an integer number (2194487241).

Almost surely, 2^21220324025 is an apocalyptic number.

21220324025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21220324025 is a deficient number, since it is larger than the sum of its proper divisors (5113522867).

21220324025 is a wasteful number, since it uses less digits than its factorization.

21220324025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665980 (or 665975 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

Adding to 21220324025 its reverse (52042302212), we get a palindrome (73262626237).

The spelling of 21220324025 in words is "twenty-one billion, two hundred twenty million, three hundred twenty-four thousand, twenty-five".