66550000 has 120 divisors (see below), whose sum is σ = 177269904. Its totient is φ = 24200000.

The previous prime is 66549991. The next prime is 66550009. The reversal of 66550000 is 5566.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is an interprime number because it is at equal distance from previous prime (66549991) and next prime (66550009).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66550009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6049995 + ... + 6050005.

Almost surely, 2^66550000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66550000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88634952).

66550000 is an abundant number, since it is smaller than the sum of its proper divisors (110719904).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66550000 is an frugal number, since it uses more digits than its factorization.

66550000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 22.

The square root of 66550000 is about 8157.8183358052. The cubic root of 66550000 is about 405.2434648504.

Adding to 66550000 its reverse (5566), we get a palindrome (66555566).

The spelling of 66550000 in words is "sixty-six million, five hundred fifty thousand".