21250313 has 8 divisors (see below), whose sum is σ = 24509760. Its totient is φ = 18046800.

The previous prime is 21250309. The next prime is 21250331. The reversal of 21250313 is 31305212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21250313 - 2² = 21250309 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21250291 and 21250300.

It is not an unprimeable number, because it can be changed into a prime (21250393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13163 + ... + 14688.

It is an arithmetic number, because the mean of its divisors is an integer number (3063720).

Almost surely, 2^21250313 is an apocalyptic number.

It is an amenable number.

21250313 is a deficient number, since it is larger than the sum of its proper divisors (3259447).

21250313 is a wasteful number, since it uses less digits than its factorization.

21250313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27967.

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

The square root of 21250313 is about 4609.8061781381. The cubic root of 21250313 is about 276.9842727628.

Adding to 21250313 its reverse (31305212), we get a palindrome (52555525).

The spelling of 21250313 in words is "twenty-one million, two hundred fifty thousand, three hundred thirteen".