660654121 has 2 divisors, whose sum is σ = 660654122. Its totient is φ = 660654120.

The previous prime is 660654109. The next prime is 660654131. The reversal of 660654121 is 121456066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 549246096 + 111408025 = 23436^2 + 10555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-660654121 is a prime.

It is not a weakly prime, because it can be changed into another prime (660654101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330327060 + 330327061.

It is an arithmetic number, because the mean of its divisors is an integer number (330327061).

Almost surely, 2^660654121 is an apocalyptic number.

It is an amenable number.

660654121 is a deficient number, since it is larger than the sum of its proper divisors (1).

660654121 is an equidigital number, since it uses as much as digits as its factorization.

660654121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 660654121 is about 25703.1928172358. The cubic root of 660654121 is about 870.9463085823.

The spelling of 660654121 in words is "six hundred sixty million, six hundred fifty-four thousand, one hundred twenty-one".