505121321 has 4 divisors (see below), whose sum is σ = 505271892. Its totient is φ = 504970752.

The previous prime is 505121303. The next prime is 505121341. The reversal of 505121321 is 123121505.

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 2 ways, for example, as 245266921 + 259854400 = 15661^2 + 16120^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-505121321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 505121293 and 505121302.

It is not an unprimeable number, because it can be changed into a prime (505121341) 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, 70136 + ... + 77001.

It is an arithmetic number, because the mean of its divisors is an integer number (126317973).

Almost surely, 2^505121321 is an apocalyptic number.

It is an amenable number.

505121321 is a deficient number, since it is larger than the sum of its proper divisors (150571).

505121321 is a wasteful number, since it uses less digits than its factorization.

505121321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150570.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 505121321 is about 22474.9042489618. The cubic root of 505121321 is about 796.4011896687.

Adding to 505121321 its reverse (123121505), we get a palindrome (628242826).

The spelling of 505121321 in words is "five hundred five million, one hundred twenty-one thousand, three hundred twenty-one".