21254245 has 8 divisors (see below), whose sum is σ = 26384760. Its totient is φ = 16416960.

The previous prime is 21254227. The next prime is 21254249. The reversal of 21254245 is 54245212.

It can be written as a sum of positive squares in 4 ways, for example, as 1602756 + 19651489 = 1266^2 + 4433^2 .

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

It is not a de Polignac number, because 21254245 - 2⁵ = 21254213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73146 + ... + 73435.

It is an arithmetic number, because the mean of its divisors is an integer number (3298095).

Almost surely, 2^21254245 is an apocalyptic number.

It is an amenable number.

21254245 is a deficient number, since it is larger than the sum of its proper divisors (5130515).

21254245 is a wasteful number, since it uses less digits than its factorization.

21254245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146615.

The product of its digits is 3200, while the sum is 25.

The square root of 21254245 is about 4610.2326405508. The cubic root of 21254245 is about 277.0013554131.

Adding to 21254245 its reverse (54245212), we get a palindrome (75499457).

The spelling of 21254245 in words is "twenty-one million, two hundred fifty-four thousand, two hundred forty-five".