660543403 has 4 divisors (see below), whose sum is σ = 711354448. Its totient is φ = 609732360.

The previous prime is 660543337. The next prime is 660543451. The reversal of 660543403 is 304345066.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 660543403 - 2²¹ = 658446251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660543503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25405503 + ... + 25405528.

It is an arithmetic number, because the mean of its divisors is an integer number (177838612).

Almost surely, 2^660543403 is an apocalyptic number.

660543403 is a deficient number, since it is larger than the sum of its proper divisors (50811045).

660543403 is a wasteful number, since it uses less digits than its factorization.

660543403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50811044.

The product of its (nonzero) digits is 25920, while the sum is 31.

The square root of 660543403 is about 25701.0389478713. The cubic root of 660543403 is about 870.8976523502.

Adding to 660543403 its reverse (304345066), we get a palindrome (964888469).

The spelling of 660543403 in words is "six hundred sixty million, five hundred forty-three thousand, four hundred three".