511223220 has 72 divisors (see below), whose sum is σ = 1570383360. Its totient is φ = 134596800.

The previous prime is 511223159. The next prime is 511223233. The reversal of 511223220 is 22322115.

It is a super-2 number, since 2×511223220² = 522698361334336800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 511223193 and 511223202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3756 + ... + 32195.

It is an arithmetic number, because the mean of its divisors is an integer number (21810880).

Almost surely, 2^511223220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 511223220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (785191680).

511223220 is an abundant number, since it is smaller than the sum of its proper divisors (1059160140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

511223220 is a wasteful number, since it uses less digits than its factorization.

511223220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36045 (or 36040 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 511223220 is about 22610.2459075526. The cubic root of 511223220 is about 799.5952223117.

Adding to 511223220 its reverse (22322115), we get a palindrome (533545335).

The spelling of 511223220 in words is "five hundred eleven million, two hundred twenty-three thousand, two hundred twenty".