511541821 has 6 divisors (see below), whose sum is σ = 595058910. Its totient is φ = 438464376.

The previous prime is 511541813. The next prime is 511541837. The reversal of 511541821 is 128145115.

It can be written as a sum of positive squares in only one way, i.e., 448973721 + 62568100 = 21189^2 + 7910^2 .

It is not a de Polignac number, because 511541821 - 2³ = 511541813 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 511541821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (511541861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5219766 + ... + 5219863.

It is an arithmetic number, because the mean of its divisors is an integer number (99176485).

Almost surely, 2^511541821 is an apocalyptic number.

It is an amenable number.

511541821 is a deficient number, since it is larger than the sum of its proper divisors (83517089).

511541821 is a wasteful number, since it uses less digits than its factorization.

511541821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10439643 (or 10439636 counting only the distinct ones).

The product of its digits is 1600, while the sum is 28.

The square root of 511541821 is about 22617.2903107335. The cubic root of 511541821 is about 799.7612938855.

Adding to 511541821 its reverse (128145115), we get a palindrome (639686936).

It can be divided in two parts, 51154 and 1821, that added together give a triangular number (52975 = T₃₂₅).

The spelling of 511541821 in words is "five hundred eleven million, five hundred forty-one thousand, eight hundred twenty-one".