21350225 has 24 divisors (see below), whose sum is σ = 28748160. Its totient is φ = 15635520.

The previous prime is 21350213. The next prime is 21350291. The reversal of 21350225 is 52205312.

It is not a de Polignac number, because 21350225 - 2⁸ = 21349969 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21350197 and 21350206.

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, 57992 + ... + 58358.

It is an arithmetic number, because the mean of its divisors is an integer number (1197840).

Almost surely, 2^21350225 is an apocalyptic number.

21350225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21350225 is a deficient number, since it is larger than the sum of its proper divisors (7397935).

21350225 is a wasteful number, since it uses less digits than its factorization.

21350225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 21350225 is about 4620.6303682506. The cubic root of 21350225 is about 277.4176906009.

Adding to 21350225 its reverse (52205312), we get a palindrome (73555537).

The spelling of 21350225 in words is "twenty-one million, three hundred fifty thousand, two hundred twenty-five".