21004013225 has 24 divisors (see below), whose sum is σ = 28059037440. Its totient is φ = 15504793920.

The previous prime is 21004013209. The next prime is 21004013263. The reversal of 21004013225 is 52231040012.

It is not a de Polignac number, because 21004013225 - 2⁴ = 21004013209 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21004013197 and 21004013206.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 970472 + ... + 991878.

It is an arithmetic number, because the mean of its divisors is an integer number (1169126560).

Almost surely, 2^21004013225 is an apocalyptic number.

21004013225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21004013225 is a deficient number, since it is larger than the sum of its proper divisors (7055024215).

21004013225 is a wasteful number, since it uses less digits than its factorization.

21004013225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24449 (or 24444 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 21004013225 its reverse (52231040012), we get a palindrome (73235053237).

The spelling of 21004013225 in words is "twenty-one billion, four million, thirteen thousand, two hundred twenty-five".