660616557 has 8 divisors (see below), whose sum is σ = 919118784. Its totient is φ = 421262688.

The previous prime is 660616553. The next prime is 660616571. The reversal of 660616557 is 755616066.

660616557 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 not a de Polignac number, because 660616557 - 2² = 660616553 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660616553) 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, 4787008 + ... + 4787145.

It is an arithmetic number, because the mean of its divisors is an integer number (114889848).

Almost surely, 2^660616557 is an apocalyptic number.

It is an amenable number.

660616557 is a deficient number, since it is larger than the sum of its proper divisors (258502227).

660616557 is a wasteful number, since it uses less digits than its factorization.

660616557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9574179.

The product of its (nonzero) digits is 226800, while the sum is 42.

The square root of 660616557 is about 25702.4620805089. The cubic root of 660616557 is about 870.9298012823.

The spelling of 660616557 in words is "six hundred sixty million, six hundred sixteen thousand, five hundred fifty-seven".