660971791 has 8 divisors (see below), whose sum is σ = 711941120. Its totient is φ = 611620632.

The previous prime is 660971789. The next prime is 660971807. The reversal of 660971791 is 197179066.

660971791 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 660971791 - 2¹ = 660971789 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 (660971191) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 403695 + ... + 405328.

It is an arithmetic number, because the mean of its divisors is an integer number (88992640).

Almost surely, 2^660971791 is an apocalyptic number.

660971791 is a deficient number, since it is larger than the sum of its proper divisors (50969329).

660971791 is a wasteful number, since it uses less digits than its factorization.

660971791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809085.

The product of its (nonzero) digits is 142884, while the sum is 46.

The square root of 660971791 is about 25709.3716570437. The cubic root of 660971791 is about 871.0858819594.

It can be divided in two parts, 6609 and 71791, that added together give a square (78400 = 280²).

The spelling of 660971791 in words is "six hundred sixty million, nine hundred seventy-one thousand, seven hundred ninety-one".