21403045 has 8 divisors (see below), whose sum is σ = 25716600. Its totient is φ = 17100480.

The previous prime is 21403033. The next prime is 21403049. The reversal of 21403045 is 54030412.

It can be written as a sum of positive squares in 4 ways, for example, as 5008644 + 16394401 = 2238^2 + 4049^2 .

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

It is not a de Polignac number, because 21403045 - 2⁵ = 21403013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21403049) 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, 2431 + ... + 6979.

It is an arithmetic number, because the mean of its divisors is an integer number (3214575).

Almost surely, 2^21403045 is an apocalyptic number.

It is an amenable number.

21403045 is a deficient number, since it is larger than the sum of its proper divisors (4313555).

21403045 is an equidigital number, since it uses as much as digits as its factorization.

21403045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5495.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21403045 is about 4626.3425078565. The cubic root of 21403045 is about 277.6462773425.

Adding to 21403045 its reverse (54030412), we get a palindrome (75433457).

The spelling of 21403045 in words is "twenty-one million, four hundred three thousand, forty-five".