660248639 has 4 divisors (see below), whose sum is σ = 667055424. Its totient is φ = 653441856.

The previous prime is 660248627. The next prime is 660248653. The reversal of 660248639 is 936842066.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936842066 = 2 ⋅468421033.

It is a cyclic number.

It is not a de Polignac number, because 660248639 - 2⁴ = 660248623 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 660248639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660247639) 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, 3403247 + ... + 3403440.

It is an arithmetic number, because the mean of its divisors is an integer number (166763856).

Almost surely, 2^660248639 is an apocalyptic number.

660248639 is a deficient number, since it is larger than the sum of its proper divisors (6806785).

660248639 is an equidigital number, since it uses as much as digits as its factorization.

660248639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6806784.

The product of its (nonzero) digits is 373248, while the sum is 44.

The square root of 660248639 is about 25695.3038316343. The cubic root of 660248639 is about 870.7680885855.

The spelling of 660248639 in words is "six hundred sixty million, two hundred forty-eight thousand, six hundred thirty-nine".