521225406 has 72 divisors (see below), whose sum is σ = 1294937280. Its totient is φ = 150928128.

The previous prime is 521225387. The next prime is 521225407. The reversal of 521225406 is 604522125.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 521225406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521225407) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 46675 + ... + 56753.

It is an arithmetic number, because the mean of its divisors is an integer number (17985240).

Almost surely, 2^521225406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 521225406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (647468640).

521225406 is an abundant number, since it is smaller than the sum of its proper divisors (773711874).

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

521225406 is a wasteful number, since it uses less digits than its factorization.

521225406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10130 (or 10114 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 521225406 is about 22830.3614951669. The cubic root of 521225406 is about 804.7763255986.

The spelling of 521225406 in words is "five hundred twenty-one million, two hundred twenty-five thousand, four hundred six".