66555554 has 8 divisors (see below), whose sum is σ = 107512860. Its totient is φ = 30717936.

The previous prime is 66555553. The next prime is 66555581. The reversal of 66555554 is 45555566.

It can be written as a sum of positive squares in 2 ways, for example, as 66504025 + 51529 = 8155^2 + 227^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66555553) 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, 1279889 + ... + 1279940.

Almost surely, 2^66555554 is an apocalyptic number.

66555554 is a deficient number, since it is larger than the sum of its proper divisors (40957306).

66555554 is a wasteful number, since it uses less digits than its factorization.

66555554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2559844.

The product of its digits is 450000, while the sum is 41.

The square root of 66555554 is about 8158.1587383429. The cubic root of 66555554 is about 405.2547378762.

The spelling of 66555554 in words is "sixty-six million, five hundred fifty-five thousand, five hundred fifty-four".