511921 has 4 divisors (see below), whose sum is σ = 542052. Its totient is φ = 481792.

The previous prime is 511909. The next prime is 511933. The reversal of 511921 is 129115.

511921 is nontrivially palindromic in base 7.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (511909) and next prime (511933).

It can be written as a sum of positive squares in 2 ways, for example, as 442225 + 69696 = 665^2 + 264^2 .

It is a cyclic number.

It is not a de Polignac number, because 511921 - 2⁷ = 511793 is a prime.

It is a super-2 number, since 2×511921² = 524126220482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (511961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15040 + ... + 15073.

It is an arithmetic number, because the mean of its divisors is an integer number (135513).

2⁵¹¹⁹²¹ is an apocalyptic number.

It is an amenable number.

511921 is a deficient number, since it is larger than the sum of its proper divisors (30131).

511921 is a wasteful number, since it uses less digits than its factorization.

511921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30130.

The product of its digits is 90, while the sum is 19.

The square root of 511921 is about 715.4865477422. The cubic root of 511921 is about 79.9958852050.

The spelling of 511921 in words is "five hundred eleven thousand, nine hundred twenty-one".