21245710 has 8 divisors (see below), whose sum is σ = 38242296. Its totient is φ = 8498280.

The previous prime is 21245683. The next prime is 21245713. The reversal of 21245710 is 1754212.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21245713) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1062276 + ... + 1062295.

It is an arithmetic number, because the mean of its divisors is an integer number (4780287).

Almost surely, 2^21245710 is an apocalyptic number.

21245710 is a deficient number, since it is larger than the sum of its proper divisors (16996586).

21245710 is a wasteful number, since it uses less digits than its factorization.

21245710 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2124578.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21245710 is about 4609.3068893273. The cubic root of 21245710 is about 276.9642722625.

Adding to 21245710 its reverse (1754212), we get a palindrome (22999922).

The spelling of 21245710 in words is "twenty-one million, two hundred forty-five thousand, seven hundred ten".