21461045 has 4 divisors (see below), whose sum is σ = 25753260. Its totient is φ = 17168832.

The previous prime is 21461039. The next prime is 21461053. The reversal of 21461045 is 54016412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7187761 + 14273284 = 2681^2 + 3778^2 .

It is a cyclic number.

It is not a de Polignac number, because 21461045 - 2⁴ = 21461029 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21461045.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 2146100 + ... + 2146109.

It is an arithmetic number, because the mean of its divisors is an integer number (6438315).

Almost surely, 2^21461045 is an apocalyptic number.

It is an amenable number.

21461045 is a deficient number, since it is larger than the sum of its proper divisors (4292215).

21461045 is an equidigital number, since it uses as much as digits as its factorization.

21461045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4292214.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21461045 is about 4632.6067176051. The cubic root of 21461045 is about 277.8968485376.

Adding to 21461045 its reverse (54016412), we get a palindrome (75477457).

The spelling of 21461045 in words is "twenty-one million, four hundred sixty-one thousand, forty-five".