66211500 has 96 divisors (see below), whose sum is σ = 198184896. Its totient is φ = 17164800.

The previous prime is 66211499. The next prime is 66211591. The reversal of 66211500 is 511266.

It is a happy number.

66211500 is digitally balanced in base 9, because in such base it contains all the possibile digits an equal number of times.

66211500 is strictly pandigital in base 9.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54904 + ... + 56096.

It is an arithmetic number, because the mean of its divisors is an integer number (2064426).

Almost surely, 2^66211500 is an apocalyptic number.

66211500 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 66211500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99092448).

66211500 is an abundant number, since it is smaller than the sum of its proper divisors (131973396).

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

66211500 is a wasteful number, since it uses less digits than its factorization.

66211500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1252 (or 1240 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 66211500 is about 8137.0449181506. The cubic root of 66211500 is about 404.5552196822. Note that the first 3 decimals are identical.

Adding to 66211500 its reverse (511266), we get a palindrome (66722766).

The spelling of 66211500 in words is "sixty-six million, two hundred eleven thousand, five hundred".