521393999 has 8 divisors (see below), whose sum is σ = 596849568. Its totient is φ = 446181120.

The previous prime is 521393993. The next prime is 521394001. The reversal of 521393999 is 999393125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 521393999 - 2¹⁶ = 521328463 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521393993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56042 + ... + 64679.

It is an arithmetic number, because the mean of its divisors is an integer number (74606196).

Almost surely, 2^521393999 is an apocalyptic number.

521393999 is a deficient number, since it is larger than the sum of its proper divisors (75455569).

521393999 is a wasteful number, since it uses less digits than its factorization.

521393999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121345.

The product of its digits is 590490, while the sum is 50.

The square root of 521393999 is about 22834.0534947258. The cubic root of 521393999 is about 804.8630859058.

The spelling of 521393999 in words is "five hundred twenty-one million, three hundred ninety-three thousand, nine hundred ninety-nine".