21313025 has 6 divisors (see below), whose sum is σ = 26428182. Its totient is φ = 17050400.

The previous prime is 21313021. The next prime is 21313037. The reversal of 21313025 is 52031312.

It can be written as a sum of positive squares in 3 ways, for example, as 309136 + 21003889 = 556^2 + 4583^2 .

It is not a de Polignac number, because 21313025 - 2² = 21313021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21312994 and 21313012.

It is not an unprimeable number, because it can be changed into a prime (21313021) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 426236 + ... + 426285.

It is an arithmetic number, because the mean of its divisors is an integer number (4404697).

Almost surely, 2^21313025 is an apocalyptic number.

21313025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21313025 is a deficient number, since it is larger than the sum of its proper divisors (5115157).

21313025 is an equidigital number, since it uses as much as digits as its factorization.

21313025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852531 (or 852526 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21313025 is about 4616.6031884926. The cubic root of 21313025 is about 277.2564754753.

Adding to 21313025 its reverse (52031312), we get a palindrome (73344337).

The spelling of 21313025 in words is "twenty-one million, three hundred thirteen thousand, twenty-five".