55555650661 has 8 divisors (see below), whose sum is σ = 64787931200. Its totient is φ = 47619128844.

The previous prime is 55555650649. The next prime is 55555650727. The reversal of 55555650661 is 16605655555.

It is not a de Polignac number, because 55555650661 - 2¹¹ = 55555648613 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55555650061) 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, 80984571 + ... + 80985256.

It is an arithmetic number, because the mean of its divisors is an integer number (8098491400).

Almost surely, 2^55555650661 is an apocalyptic number.

It is an amenable number.

55555650661 is a deficient number, since it is larger than the sum of its proper divisors (9232280539).

55555650661 is an equidigital number, since it uses as much as digits as its factorization.

55555650661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161969848 (or 161969834 counting only the distinct ones).

The product of its (nonzero) digits is 3375000, while the sum is 49.

The spelling of 55555650661 in words is "fifty-five billion, five hundred fifty-five million, six hundred fifty thousand, six hundred sixty-one".