20455565 has 16 divisors (see below), whose sum is σ = 26535600. Its totient is φ = 15048192.

The previous prime is 20455559. The next prime is 20455601. The reversal of 20455565 is 56555402.

It can be written as a sum of positive squares in 8 ways, for example, as 724201 + 19731364 = 851^2 + 4442^2 .

It is a cyclic number.

It is not a de Polignac number, because 20455565 - 2¹⁸ = 20193421 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24881 + ... + 25689.

It is an arithmetic number, because the mean of its divisors is an integer number (1658475).

Almost surely, 2^20455565 is an apocalyptic number.

It is an amenable number.

20455565 is a deficient number, since it is larger than the sum of its proper divisors (6080035).

20455565 is a wasteful number, since it uses less digits than its factorization.

20455565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1216.

The product of its (nonzero) digits is 30000, while the sum is 32.

The square root of 20455565 is about 4522.7828822529. The cubic root of 20455565 is about 273.4872975863.

The spelling of 20455565 in words is "twenty million, four hundred fifty-five thousand, five hundred sixty-five".