521086394 has 4 divisors (see below), whose sum is σ = 781629594. Its totient is φ = 260543196.

The previous prime is 521086393. The next prime is 521086411. The reversal of 521086394 is 493680125.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 471454369 + 49632025 = 21713^2 + 7045^2 .

It is not an unprimeable number, because it can be changed into a prime (521086393) 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 as a sum of consecutive naturals, namely, 130271597 + ... + 130271600.

Almost surely, 2^521086394 is an apocalyptic number.

521086394 is a deficient number, since it is larger than the sum of its proper divisors (260543200).

521086394 is a wasteful number, since it uses less digits than its factorization.

521086394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260543199.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 521086394 is about 22827.3168375085. The cubic root of 521086394 is about 804.7047740124.

The spelling of 521086394 in words is "five hundred twenty-one million, eighty-six thousand, three hundred ninety-four".