660242491 has 2 divisors, whose sum is σ = 660242492. Its totient is φ = 660242490.

The previous prime is 660242461. The next prime is 660242501. The reversal of 660242491 is 194242066.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 660242491 - 2⁵ = 660242459 is a prime.

It is not a weakly prime, because it can be changed into another prime (660242411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330121245 + 330121246.

It is an arithmetic number, because the mean of its divisors is an integer number (330121246).

Almost surely, 2^660242491 is an apocalyptic number.

660242491 is a deficient number, since it is larger than the sum of its proper divisors (1).

660242491 is an equidigital number, since it uses as much as digits as its factorization.

660242491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 660242491 is about 25695.1841986003. The cubic root of 660242491 is about 870.7653858164.

The spelling of 660242491 in words is "six hundred sixty million, two hundred forty-two thousand, four hundred ninety-one".