21249395 has 8 divisors (see below), whose sum is σ = 25533456. Its totient is φ = 16976736.

The previous prime is 21249331. The next prime is 21249443. The reversal of 21249395 is 59394212.

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 21249395 - 2⁶ = 21249331 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2009 + ... + 6821.

It is an arithmetic number, because the mean of its divisors is an integer number (3191682).

Almost surely, 2^21249395 is an apocalyptic number.

21249395 is a deficient number, since it is larger than the sum of its proper divisors (4284061).

21249395 is an equidigital number, since it uses as much as digits as its factorization.

21249395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5701.

The product of its digits is 19440, while the sum is 35.

The square root of 21249395 is about 4609.7066067159. The cubic root of 21249395 is about 276.9802841906.

The spelling of 21249395 in words is "twenty-one million, two hundred forty-nine thousand, three hundred ninety-five".