660345400 has 144 divisors (see below), whose sum is σ = 1818243000. Its totient is φ = 221548800.

The previous prime is 660345383. The next prime is 660345403. The reversal of 660345400 is 4543066.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660345403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 313551 + ... + 315649.

Almost surely, 2^660345400 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 660345400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (909121500).

660345400 is an abundant number, since it is smaller than the sum of its proper divisors (1157897600).

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

660345400 is a wasteful number, since it uses less digits than its factorization.

660345400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2150 (or 2130 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 660345400 is about 25697.1866164372. The cubic root of 660345400 is about 870.8106242154.

Adding to 660345400 its reverse (4543066), we get a palindrome (664888466).

It can be divided in two parts, 6603 and 45400, that added together give a triangular number (52003 = T₃₂₂).

The spelling of 660345400 in words is "six hundred sixty million, three hundred forty-five thousand, four hundred".