20555611 has 4 divisors (see below), whose sum is σ = 20663424. Its totient is φ = 20447800.

The previous prime is 20555599. The next prime is 20555641. The reversal of 20555611 is 11655502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20555611 - 2¹⁷ = 20424539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20555641) 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, 53620 + ... + 54001.

It is an arithmetic number, because the mean of its divisors is an integer number (5165856).

Almost surely, 2^20555611 is an apocalyptic number.

20555611 is a deficient number, since it is larger than the sum of its proper divisors (107813).

20555611 is a wasteful number, since it uses less digits than its factorization.

20555611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107812.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 20555611 is about 4533.8296174426. The cubic root of 20555611 is about 273.9324384545.

The spelling of 20555611 in words is "twenty million, five hundred fifty-five thousand, six hundred eleven".