20755565 has 4 divisors (see below), whose sum is σ = 24906684. Its totient is φ = 16604448.

The previous prime is 20755547. The next prime is 20755571. The reversal of 20755565 is 56555702.

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 10883401 + 9872164 = 3299^2 + 3142^2 .

It is a cyclic number.

It is not a de Polignac number, because 20755565 - 2⁸ = 20755309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2075552 + ... + 2075561.

It is an arithmetic number, because the mean of its divisors is an integer number (6226671).

Almost surely, 2^20755565 is an apocalyptic number.

It is an amenable number.

20755565 is a deficient number, since it is larger than the sum of its proper divisors (4151119).

20755565 is an equidigital number, since it uses as much as digits as its factorization.

20755565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4151118.

The product of its (nonzero) digits is 52500, while the sum is 35.

The square root of 20755565 is about 4555.8275867289. The cubic root of 20755565 is about 274.8177966618.

The spelling of 20755565 in words is "twenty million, seven hundred fifty-five thousand, five hundred sixty-five".