660320251 has 2 divisors, whose sum is σ = 660320252. Its totient is φ = 660320250.

The previous prime is 660320233. The next prime is 660320257. The reversal of 660320251 is 152023066.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 660320251 - 2¹⁵ = 660287483 is a prime.

It is not a weakly prime, because it can be changed into another prime (660320257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330160125 + 330160126.

It is an arithmetic number, because the mean of its divisors is an integer number (330160126).

Almost surely, 2^660320251 is an apocalyptic number.

660320251 is a deficient number, since it is larger than the sum of its proper divisors (1).

660320251 is an equidigital number, since it uses as much as digits as its factorization.

660320251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 660320251 is about 25696.6972780550. The cubic root of 660320251 is about 870.7995692461.

The spelling of 660320251 in words is "six hundred sixty million, three hundred twenty thousand, two hundred fifty-one".