55306661 has 4 divisors (see below), whose sum is σ = 58560012. Its totient is φ = 52053312.

The previous prime is 55306649. The next prime is 55306681. The reversal of 55306661 is 16660355.

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 44970436 + 10336225 = 6706^2 + 3215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55306661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55306621) 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, 1626650 + ... + 1626683.

It is an arithmetic number, because the mean of its divisors is an integer number (14640003).

Almost surely, 2^55306661 is an apocalyptic number.

It is an amenable number.

55306661 is a deficient number, since it is larger than the sum of its proper divisors (3253351).

55306661 is a wasteful number, since it uses less digits than its factorization.

55306661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3253350.

The product of its (nonzero) digits is 16200, while the sum is 32.

The square root of 55306661 is about 7436.8448282857. The cubic root of 55306661 is about 381.0007348149. Note that the first 3 decimals are identical.

The spelling of 55306661 in words is "fifty-five million, three hundred six thousand, six hundred sixty-one".