204122626561 has 24 divisors (see below), whose sum is σ = 253534843584. Its totient is φ = 163463176800.

The previous prime is 204122626549. The next prime is 204122626571. The reversal of 204122626561 is 165626221402.

It is a happy number.

It is not a de Polignac number, because 204122626561 - 2¹³ = 204122618369 is a prime.

It is a super-4 number, since 4×204122626561⁴ (a number of 46 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 204122626561.

It is not an unprimeable number, because it can be changed into a prime (204122626501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2057590 + ... + 2154511.

It is an arithmetic number, because the mean of its divisors is an integer number (10563951816).

Almost surely, 2^204122626561 is an apocalyptic number.

It is an amenable number.

204122626561 is a deficient number, since it is larger than the sum of its proper divisors (49412217023).

204122626561 is a wasteful number, since it uses less digits than its factorization.

204122626561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4212181 (or 4212174 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

Adding to 204122626561 its reverse (165626221402), we get a palindrome (369748847963).

The spelling of 204122626561 in words is "two hundred four billion, one hundred twenty-two million, six hundred twenty-six thousand, five hundred sixty-one".