660721027 has 4 divisors (see below), whose sum is σ = 676836216. Its totient is φ = 644605840.

The previous prime is 660721013. The next prime is 660721051. The reversal of 660721027 is 720127066.

660721027 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 720127066 = 2 ⋅360063533.

It is a cyclic number.

It is not a de Polignac number, because 660721027 - 2²³ = 652332419 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 660721027.

It is not an unprimeable number, because it can be changed into a prime (660721727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8057533 + ... + 8057614.

It is an arithmetic number, because the mean of its divisors is an integer number (169209054).

Almost surely, 2^660721027 is an apocalyptic number.

660721027 is a deficient number, since it is larger than the sum of its proper divisors (16115189).

660721027 is a wasteful number, since it uses less digits than its factorization.

660721027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16115188.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 660721027 is about 25704.4942957452. The cubic root of 660721027 is about 870.9757085183.

The spelling of 660721027 in words is "six hundred sixty million, seven hundred twenty-one thousand, twenty-seven".