1001557665 has 12 divisors (see below), whose sum is σ = 1736033364. Its totient is φ = 534164064.

The previous prime is 1001557649. The next prime is 1001557691. The reversal of 1001557665 is 5667551001.

1001557665 is a `hidden beast` number, since 10 + 0 + 15 + 576 + 65 = 666.

1001557665 is digitally balanced in base 6, 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 2 ways, for example, as 143712144 + 857845521 = 11988^2 + 29289^2 .

It is not a de Polignac number, because 1001557665 - 2⁴ = 1001557649 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11128374 + ... + 11128463.

It is an arithmetic number, because the mean of its divisors is an integer number (144669447).

Almost surely, 2^1001557665 is an apocalyptic number.

1001557665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1001557665 is a deficient number, since it is larger than the sum of its proper divisors (734475699).

1001557665 is a wasteful number, since it uses less digits than its factorization.

1001557665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22256848 (or 22256845 counting only the distinct ones).

The product of its (nonzero) digits is 31500, while the sum is 36.

The square root of 1001557665 is about 31647.3958644309. The cubic root of 1001557665 is about 1000.5189523086.

The spelling of 1001557665 in words is "one billion, one million, five hundred fifty-seven thousand, six hundred sixty-five".