55506161 has 4 divisors (see below), whose sum is σ = 55521252. Its totient is φ = 55491072.

The previous prime is 55506149. The next prime is 55506193. The reversal of 55506161 is 16160555.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 23232400 + 32273761 = 4820^2 + 5681^2 .

It is a cyclic number.

It is not a de Polignac number, because 55506161 - 2⁶ = 55506097 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (55506131) 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, 1985 + ... + 10721.

It is an arithmetic number, because the mean of its divisors is an integer number (13880313).

Almost surely, 2^55506161 is an apocalyptic number.

It is an amenable number.

55506161 is a deficient number, since it is larger than the sum of its proper divisors (15091).

55506161 is an equidigital number, since it uses as much as digits as its factorization.

55506161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15090.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 55506161 is about 7450.2457006464. The cubic root of 55506161 is about 381.4582953506.

It can be divided in two parts, 5550 and 6161, that added together give a palindrome (11711).

The spelling of 55506161 in words is "fifty-five million, five hundred six thousand, one hundred sixty-one".