1165551 has 8 divisors (see below), whose sum is σ = 1569024. Its totient is φ = 769560.

The previous prime is 1165531. The next prime is 1165579. The reversal of 1165551 is 1555611.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1165551 - 2¹⁴ = 1149167 is a prime.

It is a super-3 number, since 3×1165551³ = 4750235037533337453, which contains 333 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

1165551 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1165511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1495 + ... + 2136.

It is an arithmetic number, because the mean of its divisors is an integer number (196128).

2^1165551 is an apocalyptic number.

1165551 is a deficient number, since it is larger than the sum of its proper divisors (403473).

1165551 is a wasteful number, since it uses less digits than its factorization.

1165551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3741.

The product of its digits is 750, while the sum is 24.

The square root of 1165551 is about 1079.6068728940. The cubic root of 1165551 is about 105.2390923450.

The spelling of 1165551 in words is "one million, one hundred sixty-five thousand, five hundred fifty-one".