1015661988665 has 8 divisors (see below), whose sum is σ = 1218806490120. Its totient is φ = 812521521792.

The previous prime is 1015661988617. The next prime is 1015661988683. The reversal of 1015661988665 is 5668891665101.

1015661988665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 41974585129 + 973687403536 = 204877^2 + 986756^2 .

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 1015661988665 - 2²⁰ = 1015660940089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1015661988598 and 1015661988607.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 424010 + ... + 1486979.

It is an arithmetic number, because the mean of its divisors is an integer number (152350811265).

Almost surely, 2^{1015661988665} is an apocalyptic number.

It is an amenable number.

1015661988665 is a deficient number, since it is larger than the sum of its proper divisors (203144501455).

1015661988665 is a wasteful number, since it uses less digits than its factorization.

1015661988665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2017291.

The product of its (nonzero) digits is 18662400, while the sum is 62.

The spelling of 1015661988665 in words is "one trillion, fifteen billion, six hundred sixty-one million, nine hundred eighty-eight thousand, six hundred sixty-five".