21560461 has 4 divisors (see below), whose sum is σ = 23218972. Its totient is φ = 19901952.

The previous prime is 21560431. The next prime is 21560467. The reversal of 21560461 is 16406512.

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 5712100 + 15848361 = 2390^2 + 3981^2 .

It is a cyclic number.

It is not a de Polignac number, because 21560461 - 2⁷ = 21560333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21560467) by changing a digit.

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, 829236 + ... + 829261.

It is an arithmetic number, because the mean of its divisors is an integer number (5804743).

Almost surely, 2^21560461 is an apocalyptic number.

It is an amenable number.

21560461 is a deficient number, since it is larger than the sum of its proper divisors (1658511).

21560461 is a wasteful number, since it uses less digits than its factorization.

21560461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1658510.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21560461 is about 4643.3243479214. The cubic root of 21560461 is about 278.3252967986.

Adding to 21560461 its reverse (16406512), we get a palindrome (37966973).

The spelling of 21560461 in words is "twenty-one million, five hundred sixty thousand, four hundred sixty-one".