660681071 has 4 divisors (see below), whose sum is σ = 661226952. Its totient is φ = 660135192.

The previous prime is 660681061. The next prime is 660681113. The reversal of 660681071 is 170186066.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 660681071 - 2¹⁰ = 660680047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660681031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271121 + ... + 273546.

It is an arithmetic number, because the mean of its divisors is an integer number (165306738).

Almost surely, 2^660681071 is an apocalyptic number.

660681071 is a deficient number, since it is larger than the sum of its proper divisors (545881).

660681071 is a wasteful number, since it uses less digits than its factorization.

660681071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545880.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 660681071 is about 25703.7170658253. The cubic root of 660681071 is about 870.9581512309.

The spelling of 660681071 in words is "six hundred sixty million, six hundred eighty-one thousand, seventy-one".