66821446 has 8 divisors (see below), whose sum is σ = 102123504. Its totient is φ = 32780280.

The previous prime is 66821429. The next prime is 66821449. The reversal of 66821446 is 64412866.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66821449) 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 3 ways as a sum of consecutive naturals, for example, 315090 + ... + 315301.

It is an arithmetic number, because the mean of its divisors is an integer number (12765438).

Almost surely, 2^66821446 is an apocalyptic number.

66821446 is a deficient number, since it is larger than the sum of its proper divisors (35302058).

66821446 is a wasteful number, since it uses less digits than its factorization.

66821446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630446.

The product of its digits is 55296, while the sum is 37.

The square root of 66821446 is about 8174.4385739939. The cubic root of 66821446 is about 405.7936902258.

It can be divided in two parts, 6682 and 1446, that added together give a triangular number (8128 = T₁₂₇).

The spelling of 66821446 in words is "sixty-six million, eight hundred twenty-one thousand, four hundred forty-six".