20960561 has 4 divisors (see below), whose sum is σ = 21004800. Its totient is φ = 20916324.

The previous prime is 20960519. The next prime is 20960579. The reversal of 20960561 is 16506902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20960561 - 2⁶ = 20960497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20960501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21401 + ... + 22358.

It is an arithmetic number, because the mean of its divisors is an integer number (5251200).

Almost surely, 2^20960561 is an apocalyptic number.

It is an amenable number.

20960561 is a deficient number, since it is larger than the sum of its proper divisors (44239).

20960561 is an equidigital number, since it uses as much as digits as its factorization.

20960561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44238.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 20960561 is about 4578.2705249909. The cubic root of 20960561 is about 275.7195963714.

The spelling of 20960561 in words is "twenty million, nine hundred sixty thousand, five hundred sixty-one".