660645371 has 16 divisors (see below), whose sum is σ = 731427840. Its totient is φ = 594228960.

The previous prime is 660645367. The next prime is 660645379. The reversal of 660645371 is 173546066.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 660645371 - 2² = 660645367 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660645379) 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 in 15 ways as a sum of consecutive naturals, for example, 20636 + ... + 41798.

It is an arithmetic number, because the mean of its divisors is an integer number (45714240).

Almost surely, 2^660645371 is an apocalyptic number.

660645371 is a deficient number, since it is larger than the sum of its proper divisors (70782469).

660645371 is a wasteful number, since it uses less digits than its factorization.

660645371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21266.

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 660645371 is about 25703.0226043553. The cubic root of 660645371 is about 870.9424634972.

The spelling of 660645371 in words is "six hundred sixty million, six hundred forty-five thousand, three hundred seventy-one".