521761384493 has 4 divisors (see below), whose sum is σ = 538592396928. Its totient is φ = 504930372060.

The previous prime is 521761384489. The next prime is 521761384577. The reversal of 521761384493 is 394483167125.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 521761384493 - 2² = 521761384489 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521761384423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8415506171 + ... + 8415506232.

It is an arithmetic number, because the mean of its divisors is an integer number (134648099232).

Almost surely, 2^521761384493 is an apocalyptic number.

It is an amenable number.

521761384493 is a deficient number, since it is larger than the sum of its proper divisors (16831012435).

521761384493 is a wasteful number, since it uses less digits than its factorization.

521761384493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16831012434.

The product of its digits is 4354560, while the sum is 53.

The spelling of 521761384493 in words is "five hundred twenty-one billion, seven hundred sixty-one million, three hundred eighty-four thousand, four hundred ninety-three".