21245045 has 8 divisors (see below), whose sum is σ = 25589760. Its totient is φ = 16932240.

The previous prime is 21245033. The next prime is 21245051. The reversal of 21245045 is 54054212.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-21245045 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21245045.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 6485 + ... + 9194.

It is an arithmetic number, because the mean of its divisors is an integer number (3198720).

Almost surely, 2^21245045 is an apocalyptic number.

It is an amenable number.

21245045 is a deficient number, since it is larger than the sum of its proper divisors (4344715).

21245045 is a wasteful number, since it uses less digits than its factorization.

21245045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15955.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 21245045 is about 4609.2347521037. The cubic root of 21245045 is about 276.9613825315.

Adding to 21245045 its reverse (54054212), we get a palindrome (75299257).

The spelling of 21245045 in words is "twenty-one million, two hundred forty-five thousand, forty-five".