20055561 has 8 divisors (see below), whose sum is σ = 26761440. Its totient is φ = 13360032.

The previous prime is 20055547. The next prime is 20055569. The reversal of 20055561 is 16555002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20055561 - 2⁷ = 20055433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20055569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6301 + ... + 8933.

It is an arithmetic number, because the mean of its divisors is an integer number (3345180).

Almost surely, 2^20055561 is an apocalyptic number.

It is an amenable number.

20055561 is a deficient number, since it is larger than the sum of its proper divisors (6705879).

20055561 is a wasteful number, since it uses less digits than its factorization.

20055561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5175.

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 20055561 is about 4478.3435553785. The cubic root of 20055561 is about 271.6928888502.

The spelling of 20055561 in words is "twenty million, fifty-five thousand, five hundred sixty-one".