521551404 has 144 divisors (see below), whose sum is σ = 1513983744. Its totient is φ = 149846400.

The previous prime is 521551391. The next prime is 521551417. The reversal of 521551404 is 404155125.

It is an interprime number because it is at equal distance from previous prime (521551391) and next prime (521551417).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1575519 + ... + 1575849.

It is an arithmetic number, because the mean of its divisors is an integer number (10513776).

Almost surely, 2^521551404 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 521551404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (756991872).

521551404 is an abundant number, since it is smaller than the sum of its proper divisors (992432340).

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

521551404 is a wasteful number, since it uses less digits than its factorization.

521551404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The square root of 521551404 is about 22837.4999507389. The cubic root of 521551404 is about 804.9440718317.

The spelling of 521551404 in words is "five hundred twenty-one million, five hundred fifty-one thousand, four hundred four".