66821460 has 48 divisors (see below), whose sum is σ = 187754112. Its totient is φ = 17756800.

The previous prime is 66821449. The next prime is 66821473. The reversal of 66821460 is 6412866.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 16870 + ... + 20450.

It is an arithmetic number, because the mean of its divisors is an integer number (3911544).

Almost surely, 2^66821460 is an apocalyptic number.

66821460 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66821460 is an abundant number, since it is smaller than the sum of its proper divisors (120932652).

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

66821460 is a wasteful number, since it uses less digits than its factorization.

66821460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3904 (or 3902 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 66821460 is about 8174.4394303218. The cubic root of 66821460 is about 405.7937185655.

The spelling of 66821460 in words is "sixty-six million, eight hundred twenty-one thousand, four hundred sixty".