21051045 has 24 divisors (see below), whose sum is σ = 36777312. Its totient is φ = 11138400.

The previous prime is 21051029. The next prime is 21051047. The reversal of 21051045 is 54015012.

It is not a de Polignac number, because 21051045 - 2⁴ = 21051029 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051047) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 4110 + ... + 7680.

It is an arithmetic number, because the mean of its divisors is an integer number (1532388).

Almost surely, 2^21051045 is an apocalyptic number.

It is an amenable number.

21051045 is a deficient number, since it is larger than the sum of its proper divisors (15726267).

21051045 is a wasteful number, since it uses less digits than its factorization.

21051045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3713 (or 3710 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 21051045 is about 4588.1417807213. The cubic root of 21051045 is about 276.1157753098.

Adding to 21051045 its reverse (54015012), we get a palindrome (75066057).

The spelling of 21051045 in words is "twenty-one million, fifty-one thousand, forty-five".