1011615665 has 4 divisors (see below), whose sum is σ = 1213938804. Its totient is φ = 809292528.

The previous prime is 1011615659. The next prime is 1011615679. The reversal of 1011615665 is 5665161101.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5665161101 = 41 ⋅138174661.

It can be written as a sum of positive squares in 2 ways, for example, as 148254976 + 863360689 = 12176^2 + 29383^2 .

It is a cyclic number.

It is not a de Polignac number, because 1011615665 - 2¹² = 1011611569 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101161562 + ... + 101161571.

It is an arithmetic number, because the mean of its divisors is an integer number (303484701).

Almost surely, 2^1011615665 is an apocalyptic number.

It is an amenable number.

1011615665 is a deficient number, since it is larger than the sum of its proper divisors (202323139).

1011615665 is an equidigital number, since it uses as much as digits as its factorization.

1011615665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202323138.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 1011615665 is about 31805.9061339242. The cubic root of 1011615665 is about 1003.8569928137.

Adding to 1011615665 its reverse (5665161101), we get a palindrome (6676776766).

The spelling of 1011615665 in words is "one billion, eleven million, six hundred fifteen thousand, six hundred sixty-five".