511665 has 32 divisors (see below), whose sum is σ = 1022976. Its totient is φ = 212160.

The previous prime is 511633. The next prime is 511669. The reversal of 511665 is 566115.

It is not a de Polignac number, because 511665 - 2⁵ = 511633 is a prime.

It is a super-3 number, since 3×511665³ = 401863336860013875, which contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (511669) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 934 + ... + 1376.

It is an arithmetic number, because the mean of its divisors is an integer number (31968).

2⁵¹¹⁶⁶⁵ is an apocalyptic number.

511665 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

511665 is a deficient number, since it is larger than the sum of its proper divisors (511311).

511665 is a wasteful number, since it uses less digits than its factorization.

511665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469.

The product of its digits is 900, while the sum is 24.

The square root of 511665 is about 715.3076261302. The cubic root of 511665 is about 79.9825482766.

It can be divided in two parts, 511 and 665, that added together give a triangular number (1176 = T₄₈).

The spelling of 511665 in words is "five hundred eleven thousand, six hundred sixty-five".