55550550555561 has 16 divisors (see below), whose sum is σ = 75353638345920. Its totient is φ = 36391095866880.

The previous prime is 55550550555559. The next prime is 55550550555589. The reversal of 55550550555561 is 16555505505555.

It is not a de Polignac number, because 55550550555561 - 2¹ = 55550550555559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55550550555061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63854080 + ... + 64718193.

It is an arithmetic number, because the mean of its divisors is an integer number (4709602396620).

Almost surely, 2^{55550550555561} is an apocalyptic number.

It is an amenable number.

55550550555561 is a deficient number, since it is larger than the sum of its proper divisors (19803087790359).

55550550555561 is a wasteful number, since it uses less digits than its factorization.

55550550555561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128574776.

The product of its (nonzero) digits is 58593750, while the sum is 57.

The spelling of 55550550555561 in words is "fifty-five trillion, five hundred fifty billion, five hundred fifty million, five hundred fifty-five thousand, five hundred sixty-one".