1316551521665 has 8 divisors (see below), whose sum is σ = 1599860077440. Its totient is φ = 1039909049712.

The previous prime is 1316551521563. The next prime is 1316551521667. The reversal of 1316551521665 is 5661251556131.

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 1316551521665 - 2¹⁸ = 1316551259521 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1316551521667) 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, 1666520519 + ... + 1666521308.

It is an arithmetic number, because the mean of its divisors is an integer number (199982509680).

Almost surely, 2^{1316551521665} is an apocalyptic number.

It is an amenable number.

1316551521665 is a deficient number, since it is larger than the sum of its proper divisors (283308555775).

1316551521665 is an equidigital number, since it uses as much as digits as its factorization.

1316551521665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3333041911.

The product of its digits is 810000, while the sum is 47.

The spelling of 1316551521665 in words is "one trillion, three hundred sixteen billion, five hundred fifty-one million, five hundred twenty-one thousand, six hundred sixty-five".