521457381 has 12 divisors (see below), whose sum is σ = 779189580. Its totient is φ = 335650560.

The previous prime is 521457347. The next prime is 521457389. The reversal of 521457381 is 183754125.

521457381 is a `hidden beast` number, since 5 + 2 + 1 + 4 + 573 + 81 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 251381025 + 270076356 = 15855^2 + 16434^2 .

It is not a de Polignac number, because 521457381 - 2¹⁰ = 521456357 is a prime.

It is a super-2 number, since 2×521457381² = 543835600398758322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521457389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 998700 + ... + 999221.

It is an arithmetic number, because the mean of its divisors is an integer number (64932465).

Almost surely, 2^521457381 is an apocalyptic number.

It is an amenable number.

521457381 is a deficient number, since it is larger than the sum of its proper divisors (257732199).

521457381 is a wasteful number, since it uses less digits than its factorization.

521457381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1997956 (or 1997953 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 521457381 is about 22835.4413357833. The cubic root of 521457381 is about 804.8956983289.

The spelling of 521457381 in words is "five hundred twenty-one million, four hundred fifty-seven thousand, three hundred eighty-one".