521521400 has 96 divisors (see below), whose sum is σ = 1252152000. Its totient is φ = 201899520.

The previous prime is 521521387. The next prime is 521521411. The reversal of 521521400 is 4125125.

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 1024346 + ... + 1024854.

It is an arithmetic number, because the mean of its divisors is an integer number (13043250).

Almost surely, 2^521521400 is an apocalyptic number.

521521400 is a gapful number since it is divisible by the number (50) 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 521521400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (626076000).

521521400 is an abundant number, since it is smaller than the sum of its proper divisors (730630600).

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

521521400 is a wasteful number, since it uses less digits than its factorization.

521521400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681 (or 672 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 521521400 is about 22836.8430392644. The cubic root of 521521400 is about 804.9286358300.

Adding to 521521400 its reverse (4125125), we get a palindrome (525646525).

The spelling of 521521400 in words is "five hundred twenty-one million, five hundred twenty-one thousand, four hundred".