521404400 has 120 divisors (see below), whose sum is σ = 1376828544. Its totient is φ = 188179200.

The previous prime is 521404397. The next prime is 521404447. The reversal of 521404400 is 4404125.

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, 716837 + ... + 717563.

Almost surely, 2^521404400 is an apocalyptic number.

521404400 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 521404400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (688414272).

521404400 is an abundant number, since it is smaller than the sum of its proper divisors (855424144).

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

521404400 is a wasteful number, since it uses less digits than its factorization.

521404400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919 (or 908 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 521404400 is about 22834.2812455308. The cubic root of 521404400 is about 804.8684377928.

Adding to 521404400 its reverse (4404125), we get a palindrome (525808525).

The spelling of 521404400 in words is "five hundred twenty-one million, four hundred four thousand, four hundred".