55405061561 has 4 divisors (see below), whose sum is σ = 55634958324. Its totient is φ = 55175164800.

The previous prime is 55405061521. The next prime is 55405061567. The reversal of 55405061561 is 16516050455.

It is a happy number.

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 41481061561 + 13924000000 = 203669^2 + 118000^2 .

It is a cyclic number.

It is not a de Polignac number, because 55405061561 - 2¹⁰ = 55405060537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55405061567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114948020 + ... + 114948501.

It is an arithmetic number, because the mean of its divisors is an integer number (13908739581).

Almost surely, 2^55405061561 is an apocalyptic number.

It is an amenable number.

55405061561 is a deficient number, since it is larger than the sum of its proper divisors (229896763).

55405061561 is a wasteful number, since it uses less digits than its factorization.

55405061561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229896762.

The product of its (nonzero) digits is 90000, while the sum is 38.

The spelling of 55405061561 in words is "fifty-five billion, four hundred five million, sixty-one thousand, five hundred sixty-one".