521945424 has 640 divisors, whose sum is σ = 2159861760. Its totient is φ = 116121600.

The previous prime is 521945399. The next prime is 521945429. The reversal of 521945424 is 424549125.

It is a happy number.

521945424 is a `hidden beast` number, since 5 + 21 + 94 + 542 + 4 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521945429) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7351309 + ... + 7351379.

It is an arithmetic number, because the mean of its divisors is an integer number (3374784).

Almost surely, 2^521945424 is an apocalyptic number.

521945424 is a gapful number since it is divisible by the number (54) 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 521945424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1079930880).

521945424 is an abundant number, since it is smaller than the sum of its proper divisors (1637916336).

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

521945424 is a wasteful number, since it uses less digits than its factorization.

521945424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 124 counting only the distinct ones).

The product of its digits is 57600, while the sum is 36.

The square root of 521945424 is about 22846.1249230586. The cubic root of 521945424 is about 805.1467263378.

The spelling of 521945424 in words is "five hundred twenty-one million, nine hundred forty-five thousand, four hundred twenty-four".