1000661016555 has 24 divisors (see below), whose sum is σ = 1794288721680. Its totient is φ = 515282913600.

The previous prime is 1000661016493. The next prime is 1000661016577. The reversal of 1000661016555 is 5556101660001.

It is not a de Polignac number, because 1000661016555 - 2²⁵ = 1000627462123 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 383393721 + ... + 383396330.

It is an arithmetic number, because the mean of its divisors is an integer number (74762030070).

Almost surely, 2^{1000661016555} is an apocalyptic number.

1000661016555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1000661016555 is a deficient number, since it is larger than the sum of its proper divisors (793627705125).

1000661016555 is a wasteful number, since it uses less digits than its factorization.

1000661016555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766790091 (or 766790088 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 36.

Adding to 1000661016555 its reverse (5556101660001), we get a palindrome (6556762676556).

The spelling of 1000661016555 in words is "one trillion, six hundred sixty-one million, sixteen thousand, five hundred fifty-five".