660438929 has 2 divisors, whose sum is σ = 660438930. Its totient is φ = 660438928.

The previous prime is 660438923. The next prime is 660438931. The reversal of 660438929 is 929834066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 496086529 + 164352400 = 22273^2 + 12820^2 .

It is a cyclic number.

It is not a de Polignac number, because 660438929 - 2¹² = 660434833 is a prime.

Together with 660438931, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (660438923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330219464 + 330219465.

It is an arithmetic number, because the mean of its divisors is an integer number (330219465).

Almost surely, 2^660438929 is an apocalyptic number.

It is an amenable number.

660438929 is a deficient number, since it is larger than the sum of its proper divisors (1).

660438929 is an equidigital number, since it uses as much as digits as its factorization.

660438929 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 559872, while the sum is 47.

The square root of 660438929 is about 25699.0063815705. The cubic root of 660438929 is about 870.8517351260.

The spelling of 660438929 in words is "six hundred sixty million, four hundred thirty-eight thousand, nine hundred twenty-nine".