66855000 has 80 divisors (see below), whose sum is σ = 208901880. Its totient is φ = 17824000.

The previous prime is 66854993. The next prime is 66855001. The reversal of 66855000 is 55866.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66855001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12772 + ... + 17228.

Almost surely, 2^66855000 is an apocalyptic number.

66855000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66855000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104450940).

66855000 is an abundant number, since it is smaller than the sum of its proper divisors (142046880).

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

66855000 is a wasteful number, since it uses less digits than its factorization.

66855000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4486 (or 4467 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 66855000 is about 8176.4906897764. The cubic root of 66855000 is about 405.8616011729.

The spelling of 66855000 in words is "sixty-six million, eight hundred fifty-five thousand".