21560545 has 16 divisors (see below), whose sum is σ = 27578880. Its totient is φ = 16143424.

The previous prime is 21560507. The next prime is 21560549. The reversal of 21560545 is 54506512.

It is not a de Polignac number, because 21560545 - 2¹³ = 21552353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21560549) 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 15 ways as a sum of consecutive naturals, for example, 3411 + ... + 7399.

It is an arithmetic number, because the mean of its divisors is an integer number (1723680).

Almost surely, 2^21560545 is an apocalyptic number.

It is an amenable number.

21560545 is a deficient number, since it is larger than the sum of its proper divisors (6018335).

21560545 is a wasteful number, since it uses less digits than its factorization.

21560545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4064.

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 21560545 is about 4643.3333931563. Note that the first 4 decimals coincide. The cubic root of 21560545 is about 278.3256582519.

The spelling of 21560545 in words is "twenty-one million, five hundred sixty thousand, five hundred forty-five".