21130545 has 8 divisors (see below), whose sum is σ = 33808896. Its totient is φ = 11269616.

The previous prime is 21130511. The next prime is 21130573. The reversal of 21130545 is 54503112.

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

It is a cyclic number.

It is not a de Polignac number, because 21130545 - 2⁶ = 21130481 is a prime.

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, 704337 + ... + 704366.

It is an arithmetic number, because the mean of its divisors is an integer number (4226112).

Almost surely, 2^21130545 is an apocalyptic number.

It is an amenable number.

21130545 is a deficient number, since it is larger than the sum of its proper divisors (12678351).

21130545 is a wasteful number, since it uses less digits than its factorization.

21130545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1408711.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21130545 is about 4596.7972546111. The cubic root of 21130545 is about 276.4629255947.

Adding to 21130545 its reverse (54503112), we get a palindrome (75633657).

The spelling of 21130545 in words is "twenty-one million, one hundred thirty thousand, five hundred forty-five".