66404000 has 96 divisors (see below), whose sum is σ = 175842576. Its totient is φ = 24499200.

The previous prime is 66403933. The next prime is 66404027. The reversal of 66404000 is 40466.

It can be written as a sum of positive squares in 8 ways, for example, as 274576 + 66129424 = 524^2 + 8132^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 51362 + ... + 52638.

Almost surely, 2^66404000 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 66404000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87921288).

66404000 is an abundant number, since it is smaller than the sum of its proper divisors (109438576).

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

66404000 is a wasteful number, since it uses less digits than its factorization.

66404000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1315 (or 1297 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 66404000 is about 8148.8649516359. The cubic root of 66404000 is about 404.9469015384.

Adding to 66404000 its reverse (40466), we get a palindrome (66444466).

The spelling of 66404000 in words is "sixty-six million, four hundred four thousand".