55321666 has 4 divisors (see below), whose sum is σ = 82982502. Its totient is φ = 27660832.

The previous prime is 55321661. The next prime is 55321667. The reversal of 55321666 is 66612355.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66612355 = 5 ⋅13322471.

It can be written as a sum of positive squares in only one way, i.e., 54331641 + 990025 = 7371^2 + 995^2 .

It is not an unprimeable number, because it can be changed into a prime (55321661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13830415 + ... + 13830418.

Almost surely, 2^55321666 is an apocalyptic number.

55321666 is a deficient number, since it is larger than the sum of its proper divisors (27660836).

55321666 is a wasteful number, since it uses less digits than its factorization.

55321666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27660835.

The product of its digits is 32400, while the sum is 34.

The square root of 55321666 is about 7437.8535882336. The cubic root of 55321666 is about 381.0351875612.

The spelling of 55321666 in words is "fifty-five million, three hundred twenty-one thousand, six hundred sixty-six".