661273147 has 2 divisors, whose sum is σ = 661273148. Its totient is φ = 661273146.

The previous prime is 661273141. The next prime is 661273177. The reversal of 661273147 is 741372166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 661273147 - 2¹¹ = 661271099 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (661273141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330636573 + 330636574.

It is an arithmetic number, because the mean of its divisors is an integer number (330636574).

Almost surely, 2^661273147 is an apocalyptic number.

661273147 is a deficient number, since it is larger than the sum of its proper divisors (1).

661273147 is an equidigital number, since it uses as much as digits as its factorization.

661273147 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 37.

The square root of 661273147 is about 25715.2318091827. The cubic root of 661273147 is about 871.2182461923.

The spelling of 661273147 in words is "six hundred sixty-one million, two hundred seventy-three thousand, one hundred forty-seven".