1115665551 has 96 divisors (see below), whose sum is σ = 2222857728. Its totient is φ = 520369920.

The previous prime is 1115665549. The next prime is 1115665553. The reversal of 1115665551 is 1555665111.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1115665549) and next prime (1115665553).

It is not a de Polignac number, because 1115665551 - 2¹ = 1115665549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1115665553) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 331660 + ... + 335006.

It is an arithmetic number, because the mean of its divisors is an integer number (23154768).

Almost surely, 2^1115665551 is an apocalyptic number.

1115665551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1115665551 is a deficient number, since it is larger than the sum of its proper divisors (1107192177).

1115665551 is a wasteful number, since it uses less digits than its factorization.

1115665551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3421 (or 3418 counting only the distinct ones).

The product of its digits is 22500, while the sum is 36.

The square root of 1115665551 is about 33401.5800674160. The cubic root of 1115665551 is about 1037.1574098169.

It can be divided in two parts, 1115 and 665551, that added together give a palindrome (666666).

The spelling of 1115665551 in words is "one billion, one hundred fifteen million, six hundred sixty-five thousand, five hundred fifty-one".