206556655601 has 4 divisors (see below), whose sum is σ = 208451670900. Its totient is φ = 204661640304.

The previous prime is 206556655597. The next prime is 206556655603. The reversal of 206556655601 is 106556655602.

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 114006847201 + 92549808400 = 337649^2 + 304220^2 .

It is a cyclic number.

It is not a de Polignac number, because 206556655601 - 2² = 206556655597 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206556655603) 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, 947507486 + ... + 947507703.

It is an arithmetic number, because the mean of its divisors is an integer number (52112917725).

Almost surely, 2^206556655601 is an apocalyptic number.

It is an amenable number.

206556655601 is a deficient number, since it is larger than the sum of its proper divisors (1895015299).

206556655601 is a wasteful number, since it uses less digits than its factorization.

206556655601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1895015298.

The product of its (nonzero) digits is 1620000, while the sum is 47.

Subtracting from 206556655601 its reverse (106556655602), we obtain a palindrome (99999999999).

The spelling of 206556655601 in words is "two hundred six billion, five hundred fifty-six million, six hundred fifty-five thousand, six hundred one".