500018685521 has 4 divisors (see below), whose sum is σ = 500022219444. Its totient is φ = 500015151600.

The previous prime is 500018685457. The next prime is 500018685541. The reversal of 500018685521 is 125586810005.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125586810005 = 5 ⋅25117362001.

It can be written as a sum of positive squares in 2 ways, for example, as 407426890000 + 92591795521 = 638300^2 + 304289^2 .

It is a cyclic number.

It is not a de Polignac number, because 500018685521 - 2⁶ = 500018685457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (500018685541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1545470 + ... + 1840791.

It is an arithmetic number, because the mean of its divisors is an integer number (125005554861).

Almost surely, 2^500018685521 is an apocalyptic number.

It is an amenable number.

500018685521 is a deficient number, since it is larger than the sum of its proper divisors (3533923).

500018685521 is a wasteful number, since it uses less digits than its factorization.

500018685521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3533922.

The product of its (nonzero) digits is 96000, while the sum is 41.

The spelling of 500018685521 in words is "five hundred billion, eighteen million, six hundred eighty-five thousand, five hundred twenty-one".