505721011 has 4 divisors (see below), whose sum is σ = 522034624. Its totient is φ = 489407400.

The previous prime is 505720997. The next prime is 505721017. The reversal of 505721011 is 110127505.

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

It is a cyclic number.

It is not a de Polignac number, because 505721011 - 2⁹ = 505720499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (505721017) 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, 8156760 + ... + 8156821.

It is an arithmetic number, because the mean of its divisors is an integer number (130508656).

Almost surely, 2^505721011 is an apocalyptic number.

505721011 is a deficient number, since it is larger than the sum of its proper divisors (16313613).

505721011 is a wasteful number, since it uses less digits than its factorization.

505721011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16313612.

The product of its (nonzero) digits is 350, while the sum is 22.

The square root of 505721011 is about 22488.2416164537. The cubic root of 505721011 is about 796.7162327624.

Adding to 505721011 its reverse (110127505), we get a palindrome (615848516).

The spelling of 505721011 in words is "five hundred five million, seven hundred twenty-one thousand, eleven".