521821872 has 160 divisors (see below), whose sum is σ = 1759887360. Its totient is φ = 145946880.

The previous prime is 521821829. The next prime is 521821891. The reversal of 521821872 is 278128125.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 57553 + ... + 65999.

It is an arithmetic number, because the mean of its divisors is an integer number (10999296).

Almost surely, 2^521821872 is an apocalyptic number.

521821872 is a gapful number since it is divisible by the number (52) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521821872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (879943680).

521821872 is an abundant number, since it is smaller than the sum of its proper divisors (1238065488).

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

521821872 is a wasteful number, since it uses less digits than its factorization.

521821872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8488 (or 8476 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 521821872 is about 22843.4207595973. The cubic root of 521821872 is about 805.0831913819.

Adding to 521821872 its reverse (278128125), we get a palindrome (799949997).

The spelling of 521821872 in words is "five hundred twenty-one million, eight hundred twenty-one thousand, eight hundred seventy-two".