21560045 has 8 divisors (see below), whose sum is σ = 27862296. Its totient is φ = 15921216.

The previous prime is 21560027. The next prime is 21560047. The reversal of 21560045 is 54006512.

It can be written as a sum of positive squares in 4 ways, for example, as 3556996 + 18003049 = 1886^2 + 4243^2 .

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 21560045 - 2²⁴ = 4782829 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21560045.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21560047) 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, 165782 + ... + 165911.

It is an arithmetic number, because the mean of its divisors is an integer number (3482787).

Almost surely, 2^21560045 is an apocalyptic number.

It is an amenable number.

21560045 is a deficient number, since it is larger than the sum of its proper divisors (6302251).

21560045 is a wasteful number, since it uses less digits than its factorization.

21560045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331711.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 21560045 is about 4643.2795522131. The cubic root of 21560045 is about 278.3235067307.

Adding to 21560045 its reverse (54006512), we get a palindrome (75566557).

The spelling of 21560045 in words is "twenty-one million, five hundred sixty thousand, forty-five".