1000665551 has 4 divisors (see below), whose sum is σ = 1014759504. Its totient is φ = 986571600.

The previous prime is 1000665541. The next prime is 1000665607. The reversal of 1000665551 is 1555660001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1555660001 = 7 ⋅222237143.

It is a cyclic number.

It is not a de Polignac number, because 1000665551 - 2¹⁸ = 1000403407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000665521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7046870 + ... + 7047011.

It is an arithmetic number, because the mean of its divisors is an integer number (253689876).

Almost surely, 2^1000665551 is an apocalyptic number.

1000665551 is a deficient number, since it is larger than the sum of its proper divisors (14093953).

1000665551 is an equidigital number, since it uses as much as digits as its factorization.

1000665551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14093952.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 1000665551 is about 31633.2981366155. The cubic root of 1000665551 is about 1000.2218011340.

It can be divided in two parts, 10006 and 65551, that added together give a palindrome (75557).

The spelling of 1000665551 in words is "one billion, six hundred sixty-five thousand, five hundred fifty-one".