1656665559987 has 8 divisors (see below), whose sum is σ = 2211611075520. Its totient is φ = 1103081875560.

The previous prime is 1656665559937. The next prime is 1656665560001. The reversal of 1656665559987 is 7899555666561.

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

It is not a de Polignac number, because 1656665559987 - 2¹⁰ = 1656665558963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1656665559907) 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, 340454937 + ... + 340459802.

It is an arithmetic number, because the mean of its divisors is an integer number (276451384440).

Almost surely, 2^{1656665559987} is an apocalyptic number.

1656665559987 is a deficient number, since it is larger than the sum of its proper divisors (554945515533).

1656665559987 is an equidigital number, since it uses as much as digits as its factorization.

1656665559987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680915553.

The product of its digits is 3674160000, while the sum is 78.

The spelling of 1656665559987 in words is "one trillion, six hundred fifty-six billion, six hundred sixty-five million, five hundred fifty-nine thousand, nine hundred eighty-seven".